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Porm A. (Membership Application)
INSTITUTE OF METALS.
Founded 1908. Incorporated 1910.
To the Secretary,
I, the iindersigned , being
of the required age and desirous of becoming a Member of
the Institcte op Metals, agree that I will be governed by the regulations of the Associa-
tion as they are now formed, or as they may be hereafter altered, and that I will advance
the interests of the Association as far as may be in my power ; and we, the undersigned,
from our personal knowledge, do hereby recommend him for election.
Name in full
Address
Business or Profession.
Qualifications
Signature
Dated this day of , 191
Signatures
of tiuBe
Members
The Council, having considered the above recommendation,
present Mr to be Balloted for as a
Member of the Institute of Metals.
To be filled up
by the
Council
36 WiCTOKLk Steebt, Chairman.
Westminstee, London, S.W. 1.
Daied this day of 191
FoK QtrALincATioNS OF Membbbs, see Section I. other side.
(U would he a convenienoe if the Candidate' 3 Card were sent teith this form.)
XIX.
EXTRACTS FROM THE RULES.
(MEMORANDUM AND ARTICLES OF ASSOCIATION.)
SECTION I.— CONSTITtJTION.
Rule 4. — Members of the Association shall be either Honorary Members, Fellows, Ordinaijr
Members, or Student Members. I
Rule 5. — Ordinary Members shall be more than twenty-three years of age, and shall be
persons occupying responsible positions. They shall be —
either (a) persons engaged in the manufacture, working, or use of non-ferrous metali
and alloys ;
or (6) persons of scientific, technical, or literary attainments connected with or interested
in the metal trades or with the application of non-ferrous metals and alloys.
Student Members shall be more than seventeen years of hge, and shall not remain Student
Members of the Association after they are twenty-five years of age, and shall be —
either (o) Students of Metallurgy ;
or (6) pupils or assistants of persons qualified for ordinary membership whether such
persons are actually members of the Association or not.
Student Members shall not be eligible for election on the Council nor entitled to vote au the
Meetings of the Association.
SECTION II.— ELECTION OF MEMBERS.
Rule 6. — Applications for membership shall be in writing in the form marked " A," and such
application must be signed by the applicant and not less than three members of the Association.
Rule 7. — Such applications for membership as Ordinary Members or Student Members as are
approved by the Council shall be inserted in voting lists. These voting lists will constitute the
ballot papers, and will specify the name, occupation, address, and proposers of each candidate.
They shall bo forwarded to the members for return to the Secretary at a fixed date, and four,
fifths of the votes recorded shall be necessary for the election of any person.
Every such election shall be subject to the payment by the applicant of his entrance fee and
first annual subscription, and he shall not become a member of the Association nor be entered
on the Register of Members until such sums are actually received from him. In the event of his
failing to pay such sums within the time specified in the notification to him of his election, hia
election shall be void.
Rule 8. — Upon election under the preceding Article the Secretary shall forward to the appli-
cant so elected notice thereof in writing in the form marked " B."
Rul> 9. — In the case of non-election, no mention thereof shall be made in the minutes.
SECTION VI.— SUBSCRIPTIONS
Rule 28. — The subscription of each Ordinary Member shall be two guineas per annum, and
of each Student Member one guinea per annum. Ordinary Members shall pay an entrance fee ot
two guineas each, and Students an entrance fee of one guinea each.
Rule 29. — Subscriptions shall be payable in advance on July Istin eaoh year, save in the case
of Ordinary Members and Student Members elected under Clauses 6 and 7 hereof, whose entrance
fee and annual subscription shall become payable in accordance with the notification to them of
their election. Every subscription shall cover the period down to the 30th of June next following,
and no longer.
Rule 30. — Subject to the provisions of Clause 7 hereof, any member whose subscfiption shall
be six months in arrear shall forfeit temporarily all the privileges of the Aseociation. Due notice
on the form following marked " C " shall be given to such member, and if such subscription
remains unpaid upon the date specified for payment in this notice, the Council may remove such
member from the Register of Members of the Association, and thereupon any member whose
name is so removed shall cease to be a member thereof, but shall nevertheless remain liable to
the Association for such arrears.
Ellicft & Fry, Ltd.]
Professor H. C. H. CARPENTER. M.A.. Ph.D., A.R.S.M., F.R.S.
President.
{.Frontispiece.
No. 1
1918
THE JOURNAL
OF THE
INSTITUTE OF METALS
VOLUME XIX
EDITED BY
G. SHAW SCOTT, M.Sc.
SSOBBTABY
(Right of Piiblication and Translation is reserved)
LONDON
PUBLISHED BY THE INSTITUTE OF METALS
36 VICTORIA STREET, WESTMINSTER, S.W.
1918
Copyright]
[Entered at Stationers' Hall
2.0D
AT THE BALLANTYNE PRESS
PRINTED BV SPOTTISWOODE, BAI.I.ANTVNE AND CO. LTD.
COLCHESTER. LONDON AND ETON. ENGLAND
THE INSTITUTE OF METALS
President.
Professor H. C. H. Carpenter, F.R.S., M.A., Ph.D. , A.R.S.M., London.
Past- Presiden ts.
Sir Gerard Mttktz, Bart., Birmingham.
Professor W. Gowland, F.R.S., A.R.S.M., London.
Professor A. K. HuKTrNGTON, A.R.S.M., London.
Engineer Vice-Admiral Sir Henry J. Oram, K.C.B., F.R.S., London.
Sir George BEiLBy, F.R.S., LL.D., London.
Vice- Presidents.
G. A. Boeddicker ....... Birmingham.
J. T. Milton London.
Sir Thomas Rose, D.Sc London.
Dr. W. RosENHAiN, F.R.S Teddington.
L. Sumner, O.B.E, M.Sc. . . . . . . Manchester.
Professor T. Turner, M.Sc, A.R.S.M Birmingham.
Honorary Treasurer.
A. E. Seaton, London.
Members of Council.
W. H. Allen Bedford.
L. Archbutt ........ Derbj'.
A. Cleghobn ........ Glasgow.
J. Dewrance ........ London.
Professor C. A. Edwards, D.Sc. ..... Manchester.
S. EvERED Birmingham.
Engineer Vice-Admiral Sir George Goodwin, K.C.B. . London.
Sir Robert Hadfield, Bart., F.R.S Sheffield.
G. Hughes. ........ Horwich.
R. S. Hutton, D.Sc Sheffield.
W. Murray Morrison London.
The Hon. Sir Charles Parsons, K.C.B., F.R.S. . . Newcastle-on-Tyne.
Arnold Phtlip, B.Sc, A.R.S.M Portsmouth.
Sir William Smith, C.B London.
The Rt. Hon. Sir William WEm Glasgow.
Hon. Auditor.
G. G. POPPLETON, F.C.A., Birmingham.
Telegraphic Address — "Victoria, 2320, London."
THE INSTTTOTE OP METALS,
36 Victoria strkbt, westminstbb, London, s.W. i.
Secretary and Editor.
G. Shaw Scott, M.Sc.
TrfepAone— Victoria, 2320.
June 1918.
CONTENTS
SECTION I.— MINUTES OF PROCEEDINGS.
PAGE
Animal General Meeting ......... 1
Report of Council .......... 1
Statements of Accounts ......... 12
Report of the Honorary Treasurer ........ 17
Election of Officers 19
Election of Members .......... 21
Election of Auditor . ......... 29
Induction of New President ......... 29
Votes of Thanks 31
Concluding Business .......... 36
Presidential Address. By Professor H. C. H. Carpenter, M.A., Ph.D.,
• A.R.S.M 37
"The Constitution of the Copper Rich Aluminium-Coppei Alloys. (Part I.
Relationship of Hardness to Constitution ). " By J. Neill Greenwood,
M.Sc. ............ 55
Discussion on ilr. Greenwood's paper . . . . .101
Communications on Mr. Greenwood's paper . . .112
" Die-Casting of Aluminium-Bronze." By H. Rix and H. Whitaker, M.Sc. . 123
Discussion on Messrs. Rix and Whitaker's paper . . . 132
Communications on Messrs. Rix and Whitaker's paper 141
" Note on Grain Siae." By G. H. GuUiver, D.Sc, F.R.S.E. . . .145
Discussion on Dr. Gulliver's Note ...... 149
" Note on Lead-Tin-Antimony Alloys." By O. W. Ellis, M.Sc. . 151
" An Investigation on Unsound Castings of Admiralty Bronze (88 : 10 : 2) ;
Its Cause and the Remedy." By Professor H. 0. H. Carpenter, M.A.,
Ph.D., A.R.S.M., and Miss C. F. Elam 155
Discussion on Professor Carpenter and Miss Elam's paper , 176
Communications on Professor Carpenter and Miss Elam's
paper 193
" Note on the Annealing of Aluminium." By R. J. Anderson, B.S., Met.E. . 221
Discu^on on Mr. Anderson's Note ..... 224
Birmingham Local Section ......... 225
Notes for Authors on the Preparation of Papers for " The Journal of the
Institute of Metals " 227
VUl
Contents
SECTION II.— ABSTRACTS OF PAPERS RELATING TO THE NON-
FERROUS METALS AND THE INDUSTRIES CONNECTED
THEREWITH.
Pkoperties of Metals and Alluys
I. Properties of luotaLs
Acetj'lcuo, action ou metals
Aluuiiuium
Annealing of metals .
Bi.'jaiuth, allotropy of
Calcium, electrical proiH-rtics of
Copper, haidncss of hard-drawn
Copper, modulus of elasticity of electrolytic
Crystal analysis by X-rays
Crystals, production of . . .
Emulsions and suspensions with molten metals
Fused metals, thermo-electric properties of.
Gold and jilatinum, colloidal
Grain size of metals ....
Lead standard electrode ....
Liquid metals, vapour pressme of
Metals, X-ray examination of .
Nickel, colloidal .....
Nickel, electrolytic behaviour of
Photo-electric effect .....
Phj'sico-chemical data for mctalluagist^
Quenching of various metals in water
Silver, action of chromic acid on
Sodium, preparation of .
Solid solutions, properties of . .
Thermo-electric effects ] . .
Titanium, metallurgy of .
Tungsten, expansion of . .
Tungsten, space-lattice of .
Vapour pressure and volatility of several hi
metals ....
X-rays and crystal structure .
X-rays, emission of .
Zinc, electrolytic
II. Properties of alloys
Acid-resisting alloys
iUuminium-bronze .
Aluminium-bronze, hardening of
Aluminium selenides .
Aluminium tellurides
Antimony selenide
Cadmium Bcleoide
gh boiling
point
Contents
IX
Dental amalgam as an absorbent for mercury
Heat treatment of 10 per cent, aluminium-coppe
Inspection of brass and bronze .
Platinum substitutes ....
Pyrophoric aUoys, electrolytic preparation of
Zinc selenide ......
III. Industrial applications
Aluminium, industrial uses
Brass -rolling mill alloys .
Bronzes for bridge construction
Die-castings, swelling of zinc alloy .
Metallurgy in Italy ....
Metal-spraying process
Nickel in Canada ....
Specifications for brass condenser tubes
Titanium, alloys of. . . .
IV. Corrosion
Condenser tubing, corrosion of .
Lead roofing, corrosion of .
Muntz metal, selective corrosion of
Method of Analysis ; Physical and Mechanical Testing ; and
Pybombtry . . . .
I. Methods of analysis
Aluminium alloys
Antimonial lead, the analysis of
Brass or bronze and babbitt analysis
Cadmiimi, detection of
Copper, iodometry of
Cupferron as a reagent
Lead, separation of iron from
Manganese, colorimetric estimation of
" Nichrome," notes on the analysis of cast
Phosphor-tin, a volumetric method for the analysis of
Phosphor-zinc, analysis of .
Platinum electrodes, substitutes for
Platinum, microchemical detection of
Recording differential dilatometer
Separation of zinc from cadmium and iodometric determination
of cadmium
Sulphide precipitates, separation of
Tin and tungsten, separation of
Tungsten powder, valuation of .
White metals, method for analysis
Zinc, eleotrometric titration of..
Zinc, sampling of .
274
274
274
275
275
275
27(j
Contents
II. Physical and mechanical testing
Brinell hardness tests
Hardness, testing of
Impact-testing methods
Test-bars in non-ferrous alloys
Testing of sheet brass
III. Pyrometry
Eutectic aUoys in pyrometry
Furnaces ; Foundry Mithods and Appliances
I. Furnaces and furnace materials .
Electric furnace for brass .
Induction furnace for melting brass
Melting furnaces
II. Foundry methods and appliances
Aluminium castings, production of
Briquetting of non-ferrous scrap
Metal melting ....
Oil furnaces for brass
Suggestions for melting brass
Use of crucibles in foundries
Elbotro-chbmistry ; Metallography .
I. Electro-chemistry
Cerium, production of, by electrolysis
Electro-deposition of nickel, the influence of super-imposed
nating current on . . .
Electrolytic nickel-plating of* aluminium
II. Metallography. ....
Cooling curves of ternary and quaternary mixtures
BlBMOQEAPHT
Subject Index
Name Index .
alter-
FAGS
276
276
277
278
278
279
280
280
281
281
281
281
282
283
283
284
284
286
286
287
288
288
288
289
290
291
291
292
294
303
LIST OF PLATES.
Professor H. C. H. Carpenter, President .
I. Illustrating Mr. Greenwood's paper
n.
Ill:
IV ,, „ »
V.
VI. to VIII.
Frontispiece
To face p. 78
79
94
95
129
IX.
Messrs. Rix and Whitaker's paper . „
Professor Carpenter and Miss Elam'a
paper . . . . between pp. 158 a?)d 159
Mr. Anderson's Note . . • . To fac€ p. 223
THE INSTITUTE OF METALS
SECTION I.
MINUTES OF PROCEEDINGS.
ANNUAL GENEEAL MEETING.
The Tenth Annual General Meeting of the Institute of
Metals was held in the Eooms of the Chemical Society, Burling-
ton House, Piccadilly, London, W., on Wednesday, March 13, and
Thursday, March 14, 1918, commencing at 8 p.m. on the first day,
when the retuing President, Sir George Beilby, LL.D., F.E.S.,
was in the Chair, and at 4 p.m. on the concluding day, when
the Chair was occupied by the President, Professor H. C. H.
Carpenter, M.A., Ph.D., A.E.S.M.
The Secretary (Mr. G. Shaw Scott, M.Sc.) read the Minutes
of the last meeting, and these were confirmed.
Eeport op Council.
The Secretary read an abstract of the following Eeport of
the Council for the year 1917 :
The Council have pleasure in submitting to the members of the
Institute of Metals, on the occasion of this, the Tenth Annual General
Meeting of the Institute, their Annual Report of the work of the
Institute for the year ended December 31, 1917.
The Coimcil have to report that the stimulating influence of war
conditions upon the activities of the Institute of Metals has continued to
make itself felt during the past year. It has told alike on the work of
the Council and its Committees and on that of individual members.
VOL. XIX. B
2 Annual General Meeting
It is gratifying to know that these activities have in the main been of
immediate value to the nation in its time of stress. In this connection
the Council have thought it right to place the resources of the Institute
freely at the disposal of the chief officials concerned with non-ferrous
metals at the Ministry of Munitions.
The more general employment of scientific metallurgists in works
engaged directly and indirectly in the production of munitions of war
has aroused the interest of t-echnical and scientific experts and of manu-
facturers in the work of the Institute, and this has led to a very large
increase in the applications for membership.
The Roll of the Institute.
The number of members on the roll of the Institute on December 31,
1917, was as follows :
Honorary Members ....... 4
Ordinary Members ....... 860
Student Members 24
Total 888
The following table shows the changes in the membership that have
taken place during the past five years :
i
Dec. 31,
1913.
Dec. 31,
1914.
Dec. 31,
1915.
Dec. 31,
1916.
Deo. 31,
1917,
Honorary Members
Ordinary Members
Student Members
Total .
3
604
19
3
628
14
2
628
10
4
648
8
4
860
24
626
646
640
660
888
The total of 888 represents a net increase of over 34 per cent, dming
the year. This is an unprecedented advance, for which the Council are
considerably indebted to activities of members in Sheffield and Bir-
mingham. As a result of steps taken to develop the membership of
the Institute in the former city 45 Members and Students were elected
during the year. In Birmingham the Local Committee on Increased
Membership was successful in adding to the Roll 83 Members and
Students. The Coimcil are particularly glad to note the increase in the
number of Student Members, but though this number (24) is now the
highest in the history of the Institute,it is felt that the Student Member-
Report of Council 3
ship class is capable of further substantial development. The Council
have the pleasure of recording that the example set in 1916 by a
lady applying for, and being elected to, membership of the Institute
has been followed during the past year by six other ladies. Of
the members of the Institute there are known to be 72 on active
service.
The Council have to record with regret the deaths of Mr. J. C.
Butterfield, Mr. J. Corfield, Mr. G. Deer, Mr. J. Gilchrist, Mr. T. W.
Hogg, Mr. G. T. Holloway, Mr. F. A. Hopkinson, Mr. K. B. Odgers, and
Sir Henry Wiggin, Bart.
General Meetings.
During the year 1917 three General Meetings have been held. The
Annual General Meeting took place in London on March 21 and 22,
the President, Sir George Beilby, LL.D., F.K.S., occupying the Chair,
At the meeting on March 21 the following communications, which are
embodied in the Journal, Vol. XVII., were presented :
1. "The General Properties of Stampings and Chill Castings in Brass of
approximately 60 : 40 Composition." By Owen William Ellis, B.Sc.
(Birmingham).
2. " Note on Machining Properties of Brass." By Owen William Ellis,
B.Sc. (Birmingham).
3. " Surface Tension and Cohesion in Metals and Alloys." By Sydney W.
Smith, D.Sc, A.R.S.M. (London).
4. " The Annealing of Nickel-Silver. Part II." By F. C. Thompson, D.Met.,
B.Sc. (Sheffield).
5. Note : " Almninium Production by Electrolysis : a Note on the Mechanism
of the Reaction." By R. Seliqman, Ph.Nat.D. (London).
The meeting on March 22 comprised a General Discussion on Metal
Melting, this being prefaced by the presentation of the following
communications— also included in Vol. XVII. :
1. "Metal Melting as practised at the Royal Mint." By W. J. Hockinq
(London).
2. " Coal -Gas as a Fuel for the Melting of Non-Ferrous Alloys." By G. B.
Beook (Sheffield).
3. " High-Pressure Gas Melting." By C. M. Waltee, B.Sc. (Birmingham).
4. " Contribution to Metal Melting Discussion." By H. M. Thoenton and
H. Haetley, M.Sc. (London).
6. " Coke-Fired Furnaces." By H. L. Reason (Birmingham).
4 Annual General Meeting
6. Note : " Aa Electric Resistance Furnace for Melting in Crucibles." By
H. C. Greenwood, D.Sc. (London), and R. S. Hutton, D.Sc. (Sheffield).
7. " Ideals and Limitations in the Melting of Non-Ferrous Metals." By
Carl Hebinq (Pa., U.S.A.).
8. Note : " Metal Melting in a Simple Crude Oil Furnace." By H. S. Prim-
rose (Ipswich).
9. Note : "A New Producer Gas-Fired Crucible Furnace." By T. Teisen,
B.Sc. (Birmingham).
The special feature of the second General Meeting of the year was the
May Lecture, which was delivered in the evening of May 3, 1917, by
Professor W. E. Dalby, M.A., F.R.S., on " Researches made possible
by the Autograph Load- Extension Optical Indicator." The President
occupied the Chair. A full report of the Lecture will be found in the
current Journal.
The third General Meeting of the Institute was held in London on
September 19, 1917. The President was in the Chair. The following
communications, which are included in the current Journal, were
presented :
1. " Experiments on the Fatigue of Brasses." By B. Parkee Haigh, D.Sc.
(Greenwich).
2. " Hardness and Hardening." By Professor T. Tttener, M.Sc., A.R.S.M,
(Birmingham).
3. " The Effects of Heat at Various Temperatures on the Rate of Softening
of Cold-RoUed Aluminium Sheet." By Professor H. C. H. Carpenter,
M.A., Ph.D., A.R.S.M. (London), and L. Tavernbr, A.R.S.M. (London).
4. Note : "A Comparison Screen for Brass." By Owen William Ellis,
M.Sc. (London).
5. " Further Notes on a High Temperature Thermostat." By J. L. Haughton,
M.Sc. (Teddington), and D.Hanson, M.Sc. (Teddington).
6. " Principles and Methods of a New System of Gas-Firing." By A. C.
loNiDES (London).
7. " Fuel Economy Possibilities in Brass-Melting Furnaces." By L. C.
Harvey (London).
8. Note : " The Effect of Great Hydrostatic Pressure on the Physical Properties
of Metals." By Professor Zay Jeffries (Cleveland, 0., U.S.A.).
9. Note : " The Use of Chromic Acid and Hydrogen Peroxide as an Etching
Agent." By S. W. Miller (Rochester, N.Y., U.S.A.).
The thanks of the Council are tendered, respectively, to the Councils
of the Chemical Society and the Institution of Civil Engineers for allow-
ing the Institute to use their buildings and rooms on the occasions of
the above-mentioned meetings.
Report of Council 5
Change of Offices.
The taking over by the Government of the Institute's former offices
at Caxton House, which was anticipated in the last Report of Council,
was efiected on February 20, 1917, when a removal was made to a suite
of offices at 36 Victoria Street, Westminster, S.W. 1. The Covmcil are
of the opinion that the members have reason to be satisfied with the
change ; the new offices are much more commodious than those formerly
occupied, and include a Reading and Writing Room, available to
members, as well as a Council Room and office accommodation. The
present suite, though commodious enough a year ago, is none too large
at present, and if the membership of the Institute continue to increase
at the rate it did in 1917 a further move may be necessary. It is
hoped, however, that by the time a further move has to be made it will
be possible to carry into efiect the scheme now under discussion for
setting up a joint building in conjunction with the Iron and Steel
Institute, the Institution of Mining and Metallurgy, and the Institution
of Mining Engineers.
Committees.
The Committees appointed by the Council in 1917 were as follows :
The Publication Committee.
C^rnVmaw— Professor A. K. Huntington.
Ordinary Members — Mr. W. H. Allen, Mr. L. Archbutt, Mr. G. A.
Boeddicker, Professor H. C. H. Carpenter, Professor W. Gowland, Sir
Robert Hadfield, Bart., Sir Thomas Rose, Dr. W. Rosenhain, Sir
William Smith, and Professor T. Turner.
- Ea;-0^ao— ThePresident.
The Finance and General Purposes Committee.
Chairman — Professor T. Turner.
Ordinary Members — Mr. G. A. Boeddicker, Professor H. C. H.
Carpenter, Mr. J. Dewrance, Mr. G. Hughes, Sir WiUiam Smith, and
Sir William Weir.
Ex-Offido — The President, Honorary Treasurer, and Chairman of
the Publication Committee.
6 Annual General Meeting
The Corrosion Research Committee.
Chairman — Professor H. C. H. Carpenter.
Ordinary Members : The Institute of Metals — Mr. L. Arclibutt,
Professor A. K. Huntington, Dr. W. Rosenhain, Sir William Smith,
Mr. Leonard Summer, and Professor Turner.
Ex-Officio — The President and Honorary Treasurer.
Admiralty — Engineer Vice-Admiral Sir George Goodwin.
Admiralty Air Service — Lieutenant Commander C. G. Jenkin.
Board of Trade— Ut. T. Carlton.
National Physical Laboratory — Sir Richard Glazebrook.
Uoyd's Register — Mr. J. T. Milton.
Institution of Electrical Engineers — Mr. J. S. Highfield.
Institute of Marine Engineers — Mr. A. Boyle.
Institution of Mechanical Engineers. — Sir Gerard Muntz, Bart.
Institution of Naval Architects — Mt. J. E. Thorny croft.
British Electrical and Allied Manufacturers^ Association — Mr. A. F.
Bennett, Mr. W. A. Dexter, and Mr. T. C. Pullman.
I The Librajjy and Museum Committee.
Chairman — Sir William Smith.
Ordinary Members — Mr. J. Dewrance, Professor A. K. Hvmtington,
Mr, W. Murray Morrison, Mr. A. Philip, and Sir Thomas Rose.
Ex-Ojfflcio — The President.
The Scientific and Industrial Research Committee.
Acting Chairman — Professor A. K. Huntington.
Ordinary Members : Manufacturers — Mr. W. Murray Morrison, Mr.
F. Tomlinson, and Mr. T. Bolton.
Academical — Professor A. K. Huntington, Dr. W. Rosenhain, and
Professor T. Turner.
Users — Mr. L. Archbutt, Mr. A. E. Seaton, and Mr. J. Dewrance;
Ex-Officio— The President.
The Nomenclature Committee.
Chairman — Dr. W. Rosenhain.
Ordinary Members : The Institute of Metals — Mr. G. A. Boeddicker,
Dr. C. H. Desch, Engineer Vice-Admiral Sir George Goodwin, Mr. G.
Hughes, Sir Gerard Muntz, Bart., Mr. A. E. Seaton, and Professor
Turner.
Report of Council 7
Admiralty — Engineer Vice-Admiral Sir George Goodwin and Mr.
C. H. Wordingham.
Institution of Electrical Engineers — Mr, W. Murray Morrison.
Institution of Engineers and Shipbuilders in Scotland — Mr. A.
Clegliorn.
Institution of Mechanical Engineers — Mr. G. Hughes.
Institution of Naval Architects — Sir William Smith.
North-East Coast Institution of Engineers and Shipbuilders — The
Hon. Sir Charles Parsons.
Society of Chemical Industry — Professor W. R. Hodgkinson.
War Office— Mr. G. H. Roberts.
Ex-Officio — The President.
The Beilby Prize Committee.
Chairman — Sir George Beilby.
Ordinary Members — Professor H. C. H. Carpenter, Dr. C. H.
Desch (Investigator), Professor A. K. Huntmgton, and Dr. W.
Rosenhain.
Ex-Officio— TIhe President.
Committee on Increased Membership.
Chairman — Professor H. C. H. Carpenter.
Ordinary Members — Mr. J. Dewrance, Mr. S. Evered, Dr. R. S.
Hutton, Dr. W. Rosenhain, Dr. R. Seligman, and Professor T. Turner.
Ex-Offix:io—The President.
Committee on Standards of Non-Ferrous Metals
AND Alloys.
Chairman — Not yet appointed.
Ordinary Members — Professor H. C. H. Carpenter, Mr. J. Dewrance,
Sir Thomas Rose, Dr. W. Rosenhain, and Sir William Smith.
Ex-Officio — The President.
Corrosion Research Committee.
The research is still being conducted with the assistance of funds
contributed by the Department of Scientific and Industrial Research,
Associations, Firms, and by the Institute. The Government grant-
in-aid has been increased during the year from £650 to £1000
per annum, the latter rate applying as from October 1, 1917. A
8 Annual General Meeting
further Government grant-in-aid of £450 lias been received, together
with a giant of a similar amount from the British Electrical and Allied
Manufacturers' Association. The aggregate sum of £900 has been
placed at the disposal of the Institute in order to carry out an investiga-
tion into the cause, or causes, of the corrosion of condenser tubes on
land by fresh water ; the research is being carried out on lines parallel
to those adopted in the case of the existing salt-water research. For
the purpose of conducting this latest investigation, a Fresh-Water
Corrosion Research Committee was appointed as a sub-committee of the
Corrosion Research Committee, four members of the 'sub-committee
representing the B.E.A.M.A. and two the Institute of Metals. At the
Council's invitation the B.E.A.M.A. have appointed three representa-
tives upon the Corrosion Research Committee.
BiRinxGHAM Local Section.
The membership of the Section for the Seventh Session was as
follows :
Members ......... 56
Associates ......... 26
Total 82
The following meetings were held during the past Session :
1916.
Tuesday, Oct. 31. Chairman's Address. By Mr. Stanley Evebed.
„ Dec. 5. Paper on " The Hardening of Metals by Work." By
Professor T. Tukxeb, M.Sc.
1917.
Tuesday, Feb. 13. Paper on " Bronze and some of its Modifications." By
F. Johnson, M.Sc.
■ Journal.
Two volumes of the Journal were published in 1917, these being
Volumes X^II. and XVIII. respectively. The number of papers and
abstracts published shows an increase as compared with the pre-war
period, as does the sale of the Journal. During the past financial year
562 copies of the Journal were sold, bringing in a revenue of £4:1 5 8s id.,
as compared ■w-ith £320 2s. \Qd. in the previous year.
Honours and Appointments.
The Coimcil are pleased to record the conferment of the honours of
a baronetcy and a knighthood respectively upon their colleagues, Sir
Robert Hadfield and Sir William Weir.
Report of Council 9
The following members have been recipients of honours during the
year :
Knights Commander of the Bath :
Engineer Vice-Admiral George G. Goodwin.
Charles Edward Ellis, Esq.
Companions of the Bath :
Engineer-Captain R. B. Dixon, R.N.
Engineer -Captain J. W, Ham, R.N. ;
Knight :
Dr. Richard T. Glazebrook, C.B., M.A., Sc.D., F.R.S.
Knights Commander of the British Empire :
Thomas Bell, Esq. Dr. George B. Hunter.
George J. Carter, Esq. James McKechnie, Esq.
Lieut.-Col. Henry Fowler. Frederick P. Preston, Esq.
Alexander Gracie, Esq., M.V.O. F. Wilfrid S. Stokes, Esq.
Commanders of the Order of the British Empire :
J. Brown, Esq. Summers Hunter, Esq.
E. E. Dendy, Esq. A. Laing, Esq.
A. S. Esslemont, Esq. A. J. C. Ross, Esq.
F. W. Harbord, Esq., A.R.S.M. H. E. Yarrow, Esq.
Professor W. R. Hodgkinson,
Ph.D., M.A.
Officers of the Order of the British Empire :
G. Cuming, Esq. J. H. Gibson, Esq.
Member of the Order of the British Empire :
H. M. Smith, Esq.
The Board of Scientific Societies having invited the appointment
of a representative of the Institute on the Board, Sir Thomas Rose
was appointed by the Council as the Institute's representative. The
Refractories Research and Standards Committee invited the Institute
to nominate representatives, and Professor A. K. Huntington and
Dr. R. S. Hutton were appointed ; a donation of £10 towards the
expenses of the Committee has been made.
Signed on behalf of the Council,
GEORGE BEILBY, President.
H. C. H. CARPENTER, Vice-President.
G. SHAW SCOTT, Secreta/ry.
March 6, 1918.
10 Annual General Meeting
The President, in moving that the Eeport be received and
adopted, said that he thought the Eeport really gave a record
of very remarkable activity in the Institute. It appeared to
him that the outstanding feature of the past year had been the
rapid development of wide co-operation. It was throughout
rather extraordinary that such a very young Institute, one of
the youngest of the technical societies, had been able to play such
a very important part in these troublous war times ; that the
members, not only members of the Council, but the individual
members, had taken such a very large place in helping in con-
nection with munitions and other matters that had come up
so urgently during the past few years. That applied to the
earlier years of the w^ar, but it applied in a very special degree
to the past year, because he had noticed very conspicuously that
the Institute was taking a more and more important place in
the appreciation of Government departments and other official
bodies. That w^as all very much to the good. The war had
been most disastrous and unfortunate, but so far as the Institute
was concerned the Institute had flourished exceedingly, not
only in its membership but in the much wider issue of making
itself felt as a really national body. He thought that had been
very largely due to the happy combination of scientific men and
industrial men and officials from Government departments.
All had from the very first co-operated in seeing that the best
use was got out of the activities of the Institute. The mere
increase in membership was in itself, of course, very gratifying ;
but it was only really gratifying if it meant that the Institute
was getting new power, new brains, and new energy, and espe-
cially getting the younger men into the Institute. It should
be clearly understood that the Institute was not only a young
body and a vigorous body, but that it wanted vigorous new blood,
young men, to carry out the modern conceptions of applied science.
Another very interesting feature, which was of especial interest
to him as retiring President, was that, although the Institute
began at the beginning of his term of office with one lady member,
he was very glad to see that six other ladies had followed the
first lady's example and become members of the Institute, and
he had a hope that the progress would be in the future geometrical
and not arithmetical. During the year the General Meetings
Annual General Meeting 11
had kept up their interest in a very remarkable way, partly owing
to the reasons he had already mentioned in connection with
important Government interests. One very interesting develop-
ment was the discussion on the use of coal-gas in the metal-
melting industry, which was a thoroughly useful and very
practical discussion. The commentary upon that really was
that, apart from all discussion and theorizing, the use of coal-gas
in metal-melting industries and metal-working industries had been
increasing, as was well known, at simply a prodigious rate. It
was rapidly becoming the case that coal-gas in industrial centres
would find an even more important outlet in industry than in
domestic use, a very significant sign of the times. With regard
to the significance and importance of the other contributions
to the meetings, the members were in a much better position to
judge than he was. In the Eeport of the Corrosion Committee
there was a reference to that body, which was a very important
example of the wide co-operative results which had come about
during the past few years, the Department of Scientific and
Industrial Eesearch. The Institute was now in very close touch
with the Department of Scientific and Industrial Eesearch, a
Government department which was advancing the Corrosion
Eesearch Committee, and tte Institute of Metals had already had
good proof that the department was very warmly sympathetic
with the most active developments of applied science, and he
thought the assistance the department had given to the Corrosion
Eesearch Committee was a very good augury for the future, that
British sympathies would be with the really practical work of the
body. He did not think there was any other point that called
for special notice, and he therefore proposed that the Eeport
be received and adopted.
Dr. 0. F. Hudson (London) seconded the motion, which
was carried unanimously.
Treasurer's Eeport.
The Secretary read an abstract of the following Accounts
and Eeport of the Treasurer :
12
Annual General Meeting
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Report of Treasurer 17
REPORT OF THE HONORARY TREASURER
(Mr. A. E. SEATON, M.Inst.CE.).
The accounts that are now presented for the past financial year
show an excess of receipts over expenditure of £698, as against an
average excess in the four preceding years of £156.
This very satisfactory increase is due partly to the larger member-
ship, but the interest on the investments made from the balances of
earlier years and the large sales of the Journal have materially helped
to improve the position.
The expenses of the current year will be considerably more than
those of the past, which was itself £120 in excess of the average of
the four preceding years. The office rent, staff charges, stationery,
and printing have all increased considerably, whOe the receipts from
investments and sales of Joiu*nal cannot do so, and the subscrip-
tions per member are constant ; the position, therefore, is that an
increase in our income at present can be attained only by an increase
in membership.
The Institute is being worked on quite economical lines, and we can
count on making ends meet for some time, but we really ought to have
a larger margin between income and expenditure to relieve those
responsible from anxiety. I am satisfied that the useful and interesting
work that has been done and is being continued by the Institute makes
it worthy of a larger support by professional and business men whose
interest is in non-ferrous metals than hitherto accorded it.
It is very desirable that our invested funds should be added to
by donations and bequests. Other similar institutions have been so
endowed, and as a result they are now able to provide Research
Scholarships, which enable still more useful work to be accomplished.
The President said he was very sorry, and Mr. Scaton him-
self was very sorry, that he could not be present personally to
present the Treasurer's Pieport. He therefore would propose
that the Report be received and adopted.
Professor T. Turner, M.Sc, Vice-President, said that he
had much pleasure in seconding the proposal that the Treasurer's
Report be received and adopted. He could not then speak to
the exact figures ; but there had been a considerable increase
of membership, as had been mentioned by the President, and
VOL. XIX. C
18 Annual General Meeting
the consequent result had been a considerable mcrease in income.
The expenditure had not increased in proportion, and as a result
the year had been the most satisfactory one financially that the
Institute had had siace it was started. It had been possible to
invest sums, which in the aggregate amounted to more than £2000,
in war loans, and there were favourable balances in each of the
accounts into which the Institute's work was divided. It was
a great pleasure to him to find that there had been such a large
increase in "membership, because it reflected the feeling of the
country with regard to the importance of scientific knowledge
at the present time. Speaking for his own district, Birmingham,
he had been very much impressed during the past twelve months
with the large number of members who attended the local section
meetings of the Institute, and the increased membership in the
other scientific societies bearing upon metallurgy and kindred
subjects. One could not help noticing the enormous increase in
scientific appliances and the development of scientific methods,
the frequency with which pyrometers were used, and the number
of firms which used the microscope, and other scientific methods
which were absolutely necessary if this country were to keep
abreast of the times. It might be perhaps thought that he was
going a little far afield from the seconding of the motion for the
adoption of the Treasurer's Eeport, but really the two things
were very closely connected. It was the demand for scientific
knowledge, and the co-operation between those who were engaged
in science at the present moment, that had enabled so satisfactory
a balance sheet to be produced.
The motion for the adoption of the Treasurer's Eeport was
then put and was carried unanimously.
The PresidiJnt, in proposing a very hearty vote of thanks
to the Treasurer, Mr. A. E. Seaton, said that those members who
attended the Council Meetings from month to month knew what
a serious amount of routine work the treasurership of the Institute
involved, and he was sure the members were very grateful indeed
to the Treasurer, who was always looked upon as a great rock in
a thirsty land : he was there to feed the wants of the Institute
and to supply the funds when they were needed, and to check
the Council when they were too enthusiastic and prevent them
Annual General Meeting 19
running into dangerous expenditure. They were therefore very
grateful to the Treasurer.
Mr. W. Murray Morrison, in seconding the motion, said
he entirely associated himself with the remarks that the President
had just made about the Treasurer, and it gave him very much
pleasure to second the vote of thanks.
The resolution of thanks was carried by acclamation.
Election op Officers.
The Secretary then announced the result of the ballot con-
cluded that day for the election of officers to replace the retiring
President, throe Vice-Presidents, and seven raembers of Council,
the list as read being as follows :
Presidemt.
Professor H. C. H. Carpenter, M.A., Ph.D., A.R.S.M.
Vice-Presidents.
Mr. G. A. Boeddicker.
Sir Thomas Kose, D.Sc.
Dr. W. RosENHAiN, F.R.S.
Members of Council.
Mr. L. Archbutt.
Professor C. A. Edwards, D.Sc.
Engineer Vice-Admiral Sir George Goodwin, K.C.B.
Sir Robert Hadfield, Bart., F.R.S.
Mr. G. Hughes.
Dr. R. S. Hutton.
Sir William Smith, C.B.
Captain G. D. Benoough, D.Sc, M.A. (London), said that
he had much pleasure in moving a vote of thanks to the retiring
Council for the work they had done during the year. He thought
under all the circumstances they should be looked upon not only
as men who had " achieved greatness " and therefore had seats
on the Council, but also as men who had " had greatness thrust
upon them." In these busy times it was, he thought, a very
great thing that they had consented to undertake to look after
all the ramifications of the work of the Institute. Looking at the
number of committees given in the Report, it would be seen that
the same names occurred over and over again, and they were
20 Annual General Meeting
practically all names of members of the Council. Each of those
committees met periodically, and the meetings were sometimes
very long. This meant that a very great amount of time was given
by the Council to the work of the Institute. He thought they
must be looked upon as office-bearers rather than as office-
holders. The term " office-bearer " rather indicated a man who
was suffering under a burden than a man who was enjoying ease
and dignity in an honourable position. The various activities,
in addition to the work of committees, which the members of the
Council had undertaken were enumerated in the Report, and
perhaps one of the most interesting to the ordinary members of
the Institute was the matter dealt with in a very brief manner in
the Eeport, where a reference was made to a scheme for a joint
building in connection with the Iron and Steel Institute, the
Institute of Mining and Metallurgy, and the Institution of Mining
Engineers. That seemed to him one of the most interesting re-
marks in the whole Eeport, and he had no doubt that it indicated
that a great deal of work of members of the Council had been
going on behind the scenes. He did not know whether it was a
hint that members of the Institution should be ready with a
little nest-egg, but he was inclined to believe that it was, and he
was sure that the members would do their best if that request
were forthcoming on their breakfast tables one morning. The
long list of Honours conferred on members spoke wonderfully
well for the Institute. Of course, a large number of those honours
had been conferred on ordinary members who had taken a very
active part in the Institute during the past few years, but he had
no doubt that later on, at the end of the war, various members of
the Council would appear in later lists in addition to those already
there. He had very much pleasure in proposing that the heartiest
thanks of the members be given to the retiring Council.
Mr. J. L. Haughton, M.Sc. (Teddington), seconded the vote
of thanks to the Council, the resolution being carried with accla-
mation.
The President said that it was very encouraging to members
of the Council to hear remarks made like those of Dr. Bengough.
He rather spoke as a neutral person because, although he had,
Annual General Meeting
21
had the honour of being the President, he had not performed as
much Council work as he ought to have done, but in all his attend-
ances at the Council he had been greatly impressed by the very
serious way in which the members took the work, and with
the large amount of work that had to be done. He thought Dr.
Bengough's suggestion of the term " office-bearer " quite honestly
applied to the Council. On the part of his colleagues he thought
he could say most safely that they had done the work with
very hearty goodwill, and that their enthusiasm for the success of
the Institute had made any labours they had performed seem
only too light, and those of them who were continuing in office
would be only too glad to watch over the interests of the
Institute in every possible way. On their behalf he thanked
the members very heartily for their appreciation in the vote
of thanks.
Election of Members.
The Secretary then read the following list of names of
candidates for membership who had been duly elected as a re.sult
of the ballots concluded on December 31, 1917, and March 13,
1918, respectively :
Members Elected December 31, 1917.
Name.
Address.
Qualifications.
Proposers.
Allday, Percy
Great Western
Director and Gen-
G. Bill-Gozzard.
William
Works, Small
eral Manager of
W. H. Henman.
Heath, Birming-
Engineering
S. Evered.
ham
Company
AntiseU, Frank
147 Water Street,
Metallurgical En-
H.C.H. Carpenter.
Linden
Perth Araboy,
gineer, Asst.
A. K. Huntington.
N.J., U.S.A.
Superintendent,
Copper Works
Consulting En-
S. L. Hoyt.
Astbury, Harry
28Broughton Road,
G. A. Boeddicker.
Hands worth.
gineer
R. S. Whipple.
Birmingham
M. T. Murray.
Batty, Robert
WharncUffe, Erd-
Works' Manager
G. Bill-Gozzard.
Be ale
ington, Birming-
W. H. Henman.
ham
S. Evered.
Braid, Arthur
120 Broadway,
Metallurgical En-
C. Vickers.
Forbes
New York City,
gineer
W. H. Bassett.
!
N.y., U.S.A.
G. C. Clamer.
22
Annual General Meeting
Name. ,
Address.
Qualifications.
Proposees.
Brown, Hugh
18 Park Hill Road,
Metallurgist and
S. W. Smith.
East Croydon,
Industrial En-
G. D. Bengough.
^
Surrey
gineer
0. F. Hudson.
Gayton, Charles
University of Mis-
Asst. Professor of
H.C.H. Carpenter.
Yancey
souri, Rolla,
Metallurgy and
A.K.Huntington.
U.S.A.
Ore Dressing
W. M. Morrison.
Cox, Ernest
The Dell, Philip
Brass Caster and
W. H. Henman.
George
Victor Road,
Metal Merchant
S. Evered.
Handsworth,
G. BiU-Gozzard.
Birmingham
Dickinson, Fred-
Palmer's Hill
Marine Engine
A. E. Seaton.
erick Thompson
Engine Works,
Builder
J. T. Milton.
Sunderland
W. S. Abell.
Dunlop, Eng. Lt.
H.M.S. Lucifer,
Engineer Lieut.
G. G. Goodwin.
Com . Samuel
c/o G.P.O.
Commander,
H. R. Teed.
Harrison
Royal Navy
J. McLaurin.
Eaton, Lt.-Col.
Mcadowside,
Asst. Inspector of
Sir G. Muntz, Bt.
Edmund
Harrow-on-the-
Munitions
E. L. Morcom.
Hill, Middlesex
E. Mapplebeck.
Fifield, Albert F.
Metal Drawing Co.,
Manufacturer
Zay Jeffries.
St. Catherine's,
C. F. Lindsay.
Ontario, Canada
H. M. Boylston.
Garland, Richard
43 Wheelwright
Metallurgist
T. Turner.
Vernon
Road, Edgbas-
S. M. Hopkins.
ton, Birmingham
H. W. Clarke.
Genders, John
270 Gillott Road,
Secretary of
G.A.Boeddicker.
Boulton
Rotton Park,
metal rolling
F. Johnson.
i
Birmingham
firm.
H. Davies.
1 Goodenough,
1 Young Street,
Gas Engineer
Sir George Beil by.
1 Francis WiUiam
Kensington Sq.,
H. M. Thornton.
i
W. 8
H. J. Yates.
Goodwin, (Miss),
" Tarana," The
Assistant to
H. C. H. Carpenter.
Winifred Mary
Ridgway,Sutton,
Corrosion Re-
G. D. Bengough.
Lenice
Surrey
search Com-
mittee
C. F. Elam.
Grabe, Alf. Ger-
Jernkontoret,
Chief Editor of
E. A. Forsberg.
hard
Stockholm,
Jernhontorets
C. Benedicks.
Sweden
Annaler
W. Rosen hain.
1 Grant, John H.,
RioTintoCo.,Ltd.,
Manager of Copper
H.C.H. Carpenter.
j A.R.S.M.
Port Talbot, S.
Works
A.K.Huntington.
!
Wales
W. M. Morrison.
Gray, James
42 Dale Road,
Asst. Technical
W. R. Twigg.
Thomas
Luton, Beds.
Manager of Fur-
H. S. Primrose.
nace Company
J. S. G. Primrose.
Griggs, Arthur
Admiralty Lab.
Engineer and Re-
H. C. H. Carpenter.
Robert
Inst, of Chemis-
search Chemist
B. Drinkwater.
try, 30 Russell
to Admiralty
L. Taverner.
Square, W.C. 1
Hammond,
32 Maple Street,
Metallographist
H. Fay.
Charles F.
New Haven,
R. S. Williams.
Conn., U.S.A.
S. L. Hoyt.
Annual General Meeting
^3
Name.
Address.
Qualifications.
Pkoposees.
Hurst, James
30 Oakley Avenue,
Metallurgical
C. A. Edwards.
Edgar
Ealing Common,
Chemist
J. L. Haughton.
W. 5
D. Hanson.
Instone, Arthur
" Beulah," Hare-
Engaged in con-
G. BiU-Gozzard.
Brian
field Road,
version of scrap
W. H. Henman.
Coventry
non-ferrous
metals
S. Evered.
Johnston, John,
3759 West Pine
Research Chemist
C. Ferry.
D.Sc.
Boiilevard, St.
W. R. Webster.
Louis, Mo.,
C. H. Mathewson.
U.S. A.
Lea, Professor
The University,
Professor of Civil
T. Turner.
Frederick
Birmingham
Engineering
S. Evered.
Charles, D.Sc.
G. Bill-Gozzard.
Merz, Charles
32 Victoria Street,
Considting En-
A. K. Huntington.
Hesterman
S.W. 1
gineer
H.C.H. Carper ter.
Sir George Beilby.
Maybrey, Her-
New Oxford and
Member of Staff,
W. Rosenhain.
bert John, B.A.
Cambridge Club,
Metallurgy De-
D. Hanson.
Pall Mall, S.W.I
partment, Nat.
Phy. Lab.
P. M. C. Routh.
Palmer, Charles
Llewellins and
Itlanufacturer and
E. P. Plenty .
Alfred
James, Ltd.,
Brass Founder
C. E. BarweU.
Castle Green,
Cyrus Braby
Bristol
Parker, James
16 CUveland Street,
Manufacturer and
W. H. Henman.
Frederick
Birmingham
Roller of Metals
S. Evered.
H. W. Clarke.
Patch, Nathaniel
Lumen Bearing
Metallurgist
J. Miller.
K. B.
Co., Buffalo,
V. Skillman.
N.Y., U.S.A.
S. L. Hoyt.
Rhodes, John
48 Wilkinson
Brass Foundry
G. Bill-Gozzard.
Henry
Street, Leigh,
Superintendent
S. M. Hopkins.
Lanes.
T. G. Hirst.
Rooney, Thomas
68 Clarence Road,
Metallurgical
W. Rosenhain.
Edmund
Teddington,
Chemist, Assist-
J. L. Haughton.
Middlesex
ant, National
Phy.sical Labo-
ratory
D. Hanson.
Shaw, Frank
Metals (Birming-
Managing Directoi
C. E. Barwell.
Norminton
ham) Ltd., Bir-
of Metal Com-
S. Evered.
mingham
pany
J. W. Madeley.
Shay, Peter
151 Pershore
Metallurgical Stu-
T. Turner.
Ye vent
Road, Edgbas-
dent, Birming-
F. Johnson.
ton, Birmingham
ham
G. Bill-Gozzard.
Shinjo, Yashio
Tokyo Electric Co.,
Director and Chief
H.C.H.Carpcnter.
Kawasaki, Kana-
Engineer of
A.K. Huntington.
gawaken, Japan
Electric Com-
pany
K. Tawara.
24
Annual General Meeting
Name.
Smith, Enoch
John
Swanson, John
Henry
Turner, Gilbert
Wagrer, William
George
Welch, John B.
Yates, George
Address.
Qualifications.
Tj'seLy Jlrtal
Iron and Brass
Works, Hay
Founder
Mill, Birming-
ham
20 Vernon Road,
Chief Examiner
KSheen, S.VV.14
(Matls.) Aero-
nautical In-
spection Di-
rectorate
43 Avondale Road,
Lecturer on Min-
Wigan
ing and Miner-
alogy
13 Emmett Street,
ManagingDirector
Limehouse, E.
of Metallurgical
14
Company
364WhaUey Ave.,
Chemical Engineer
New Hsven,
Conn., U.S.A.
29 Church Street,
Engaged in the
DubUn, Ireland
manufacture
of copper and
brass
Proposers.
G. Bill-Gozzard.
W. H. Hcnman.
S. Evercd.
C. 0. Bannister.
H. C. H. Carpenter
B. Drinkwater.
C. A. Bonnaud.
A. K. Huntington
H. C.H.Carpenter
(late)G.T. Hollo-
wav.
F. W' Harbord.
H. C. Lancaster.
H. Fav.
R. S. WilHams.
S. L. Hoyt.
G. B. Brook.
R. Ibbotson.
S. F. Derbyshire.
Students Elected December 31, 1917.
Clark, Sidney
Vowles, Thomas
19 Denison Road,
Selby, Yorks
Elm ViUa, AU
Saint's Street,
West Bromwich
Analytical
Chemist
Metal Founder
A. K. Huntington
H. C.H.Carpenter,
W. M. Morrison.
S. Evcred.
T. Turner.
G. BiU-Gozzard.
Members Elected March 13, 1918.
Bentley, Harry
Biles, Professor Sir
John Harvard
Booth, George
Wilham
Bradshaw, James
Henry Davis
Briggs, John
Waddington
Moss Lea, Sharpies
Bolton
Broadway Cham-
bers, Westmin-
ster, S.W. 1
25 Poplar Avenue,
Edgbaston,
Birmingham
i Foley Street,
Wednesbury
29 Alexandra Road,
Stafford
Mechanical En-
gineer, Director
and General
JIanager
Professor of Naval
Architecture
Expert in Refrac-
tories
Metallurgist
Engineer
G. Hughes.
C. G. Roberton.
T. G. Hirst.
A. Barr.
H. H. A. Greer.
C. H. Desch.
E. J. Smith.
S. Evered.
G. Bill-Gozzard.
Sir W. E. Smith.
Sir G. Beilby.
0. F. Hudson.
L. P. Wilks.
F. Lantsberrv.
P. A. Tucker.
Annual General Meeting
25
Name.
Address.
Qualifications.
Proposers.
Brydall, Robert
131a St. Vincent
Metal Merchant
A. Barr.
Bclhaven
Street, Glasgow
J. Steven.
H. H. A. Greer.
Cathcart, William
Marne Factory, N.
Foreman Smith
J. S. G. Primrose.
Hutton
British Loco Co.,
H. S. Primrose.
Springburn
C. H. Desch.
Chappie, Harold
Royal School of,
Metallurgist
H.C.H. Carpenter.
M., A.R.S.M.
Mines, South
W. Gowland.
Kcnsiagton
B.W. Drinkwater.
aark, Robert
138 Bath Street,
Analytical and
A. Barr.
Macfarlaue,
Glasgow
Consulting
C. H. Desch.
B.Sc.
"
Chemist
H. H. A. Greer.
Claudct, Frederic
6 Coleman Street,
Assayer
A. J. Chapman.
Herbert Bau-
E.C. 2
T. Girtin.
temps, B.A.
A. B. Suart.
Cohen, Herbert
148/9 Great Dover
Metal Manufac-
J. Steven.
Edward
Street, S.E.I
turer
A. Barr.
H. H. A. Greer.
Dexter, William
45 Scotland Street,
Mechanical En-
J. Steven.
Allinson
Glasgow
gineer
C. H. Desch.
H. H. A. Greer.
Dodwell, Albert
54 Rectory Road,
Works' Manager
N. G. Gwynne.
Ernest
Barnes, S.W. 13
J. E. Mortimer.
Sir G. Beilby.
Donaldson,
62 St. Vincent
Metal Merchant
A. Barr.
Thomas
Street, Glasgow
J. Steven.
H. H. A. Greer.
Drysdale, William
Bon Accord Works,
Engineer
A. Barr.
Yoker, Glasgow
J. Steven.
H. H. A. Greer.
Dundas, David
Archibald Watson
Engineer ; Manag-
J. Steven.
Co., Ltd., White-
ing Director
H. H. A. Greer.
inch, Glasgow
C. H. Desch.
Easdale, James
65 Washington
Metal Merchant
J. Steven.
Street, Glasgow
and Refiner
A. Barr.
H. H. A. Greer.
Easthope, Thomas
Small Arms Factory
Engineer
J. W. Varley.
Wilmot
Lithgow, New
Sir W. E. Smith.
South Wales
N. S. H. Sitwell.
Enstone, Thomas
May Fair, Rich-
Manufacturer
J. F. Kemp.
Clement
mond Hill Road,
T. Turner.
Edgbaston,
C. J. Levi.
Birmingham
Ford, Benjamin
Colinslee, Scots-
Metal Merchant
H. H. A. Greer.
tounhill.
J. A. Gardner.
Glasgow
J. Steven.
Garner, Joseph
Gormyre, Chester
Engineer
L. Sumner.
Richardson
Road, Stretford,
J. H. Rhodes.
Manchester
T. G. Hirst.
Gemmell, John
492 Argyle Street,
Metal Smelter
W. Muirhead.
Zachariah
Glasgow
and Refiner
J. Steven.
H. H. A. Greer.
1
'26
Annual General Meeting
Name.
Address.
Qualifications.
Pboposers.
George, Cecil
Oxford House,
Metallurgist at
C. A. Edwards.
Walter
Gravel Road,
Royal Aircraft
W. E. Thorneycroft.
1
Famborough,
Factory
W. Whiteley.
1
Hants
Gibson, John
21 Nigel Gardens,
Analytical Chemist
A. Barr.
Shawlands,
J. A. Gardner.
Glasgow
H. H. A. Greer.
Gilchrist, Archi-
Highfield, Kelvin-
Engineer and Ship-
A. Barr.
bald
side, Glasgow
builder
J. Steven.
H. H. A. Greer.
Goo, -ichild,
P. and W. Mac-
Manager of Metal
C. H. Desch.
Che '"Tlea
Lellan, Ltd.,
Department
J. Steven.
129 Trongate,
H. H. A. Greer.
Glasgow
Gravely, .'Tapt-
Juhan t'^tuart.
3804 Locust Street,
Chemist and Metal-
H. Fay.
Philadelpliia,
lurgist
Sir W. E. Smith.
B.A.
Penn., U.S.A.
Sir G. Beilby.
Gray, George
8 Inner Temple,
Analytical and
G. D. Cowan.
Watson
Dale Street,
Consulting
H. D. Smith.
Liverpool
Chemist
P. Davies, Jr.
Hardcastle, Eng •
Royal Naval Tor-
Inspecting Tor-
A. Cleghorn.
Com. Sydney
pedo Factory,
pedo Officer
C. W. Bryant.
UndercUffe,
Greenock
A. J. Carnt.
R.N.
Hawkcs, Eng.
7 Dunstan Road,
Superintendent,
H.C.H. Carpenter.
Com. Charles
Golders Green,
Admiralty's
Sir George Good-
John, R.N.
N.W. 2
Engineer Labo-
win.
ratory
Sir George Beilbv
Hayward, Fred.
36 1^ '^ummerfield
Metallurgical
J. W. Earle.
PhiUp Finch
Cr ascent, Edg-
Chemist
J. H. Allen. ;
bas ton, Birming-
S. Evered. 1
Herriot, WiUiam
ham
45 Scot ^and Street,
Director, Engineer-
C. H. Desch.
Scott
Glasg, iw
ing Works
J. Steven.
H. H. A. Greer.
Jackson, John
Balmoral ^on
Metal Merchant
H. H. A. Greer.
Yard, GL ^gow
J. Steven
C. H. Desch.
Judd, George
60 Little Pa. "^
Metallurgical
E. Player.
Harold
Street, Cov. ^nt^y
Chemist
F. H. Hurren.
H. L. Heathcote.
Kay, James
Manor Brass Wo ^^s
Brass Founder
L. Sumner.
Guide Bridge,
J. H. Rhodes.
Manchester
T. G. Hirst.
Kincaid, James
East Hamilton
Engineer
A. Cleghorn.
Scott
St., Greenock
Sir A. Gracie.
J. Brown.
ECing, James
121 St. Vincent
Naval Architect
A. Barr.
Foster
Street, Glasgow
C. H. Desch.
H. H. A. Greer.
Annual General Meeting
Name.
Address.
Qualifications.
Proposers.
Kipling, Herbert
Wolselcy Motors
Metallurgical
H. W. Clarke.
Spencer
Ltd., Adderlcy
Chemist
Sir W. E. Smith.
Park, Birming-
W. H. Henman.
ham
Lackie, William
75 Waterloo Street,
Electrical En-
A. Barr.
Walker
Glasgow
gineer
C. H. Desch.
H. H. A. Greer.
♦Lobnitz, Fred.
Ross Hall, Car-
Engineer and
A. Barr.
donald, Glasgow
Shipbuilder
J. Steven.
H. H. A. Greer.
Lochhead, Edwin
205 Nithsdalc
Engineer
A. Barr.
Hill
Road, Glasgow
C. H. Dcsch.
H. H. A. Greer.
Lonsdale, Lieut.
Holyrood, Lytham,
Works' Chemist
A. Ward.
Harry, M.C.
Lanes.
H. L. Rix.
J. H. Widdowson.
MacLellan, Alex-
Linthouse, Go van,
Engineer and
Sir A. Gracie.
ander Stephen
Glasgow
Shipbuilder
A. Cleghorn.
Sir G. Beilby.
McPhail, Daniel
9 Mathieson Road,
Brassfounder
J. Arnott.
Glasgow
A. Barr.
H. H. A. Greer.
McPherson, John
Dennystown Brass
Manager of Brass
W. Muirhead.
Works, Dumbar-
Works
J. Steven.
ton
H. H. A. Greer.
McQuistan, An-
Eglington Works,
Brass Bar Manu-
C. H. Desch.
drew Nisbet
Glasgow
facturer
J. Steven.
H. H. A. Greer.
Martin, Francis
A. Holt & Co.,
Analytical
W. Rosenhain.
Grimshaw,
Water Street,
Chemist
R. J. Redding.
B.Sc.
Liverpool
W. E. Gibbs.
Mechan, Henry
Scotstoun Iron
Engineer
A. Barr.
Works, Glasgow
J. Steven.
H. H. A. Greer.
Methley, Bernard
" Ferndale,"
Analyst
T. Baker.
Willoughby
Moorgate,
G. B. Brook.
Rotherham
E. A. Smith.
Morewood, Joseph
37 Paignton Road,
Departmental
G. BiU-Gozzard.
Latham
Rotton Park,
Manager
W. H. Henman.
Birmingham
A. McKechnie.
Neilson, Hugh
24 Kersland Street,
Engineer
J. Steven.
Edwin Beau-
HiUhead, Glas-
H. H. A. Greer.
mont
gow
W. Muirhead.
Osborne, Magnus
15 Osborne Street,
Metal Merchant
W. Muirhead.
Glasgow
and Mantifac-
C. H. Desch.
turer
H. H. A. Greer.
Osborne, Mark
Manor House,
Metal Merchant
W. Muirhead.
Manor Road,
and Manufac-
C. H. Desch.
Dumbreek,
turer
H. H. A. Greer.
Glasgow
* British subject. Chief of Ministry of Munitions for Scotland.
28
Annual General Meeting
Name.
Address.
Patrick, Philip
Walwin
Peakman, Percy
Pile, Frank Sey-
mour John,
M.A.
Robba, Wm.
Hugh Francis
Rothwcll, Her-
bert
Shaw, Hubert A.
Taylor, Edgar
Willmott
Turner, William
Glasier
Ward, Joseph
Stanley
Watson, Herbert
John
Wilton, John
Boswell
29/5 Cathcart
Mansions, W. 19
151 Barton Road,
Stretford, Man-
chester
Ministry of Muni-
tions, 117 Col-
more Row,
Birmingham
58 St. Vincent
Street, Glasgow
Vulco Magneto
Co., 11 Long
Acre, W.C. 2
25 Main Street,
Geneva, New
York, U.S.A.
Burra Metal Works,
64-66 Granville
Street, Birming-
ham
Eyre Street,
Sheffield
" Wymondley,"
Victoria Gardens,
Neath, S. Wales
James H. Dennis
& Co., Ltd.,
Widnes, Lanes.
87 Abbey Road,
Barrow-in-
Furness
Qualifications.
Technical Assist-
ant Ministry of
Munitions
Metallurgist
Chemist and
Metallurgist
Naval Architect
and Engineer
Electrical En-
gineer
Metallurgist
Metal Manufac-
turer
Silver Refiner
Manager (Metal
Merchants)
Metallurgical
Chemist
Metallurgical
Chemist
Pboposees.
A. Ward.
C. A. Edwards.
H. L. Rix.
C. A. Edwards.
J. H. Andrew.
W. E. Thomey-
croft.
W. R. Barclay.
G. B. Brook.
W. R. Garratt.
A. Barr.
C. H. Dcsch.
H. H. A. Greer.
F. T. F. Toller.
T. H. Turner.
E. G. King.
S. W. Miller.
H. Lee Ward.
S. L. Hoyt.
W. Plavcr.
J. W. Earle.
S. Evered.
R. J. Brown.
F. C. Thompson.
G. B. Brook.
G. Bill-Gozzard.
W. H. Henman.
J. B. Bannister.
L. Sumner.
J. H. Rhodes.
T. G. Hirst.
Sir J. McKechnie.
R. B. Ayres.
H. B. Weeks.
Students Elected March 13, 1918.
Cook, Maurice
Logan, Arthur
Martin, James
Alastair, B.Sc.
13 Victoria Place,
Hartlepool
R. and W. Haw-
thorn Leslie &
Co., Ltd., New-
castle-on-Tyne
East Chapelton
House, Bears-
den, Glasgow
Metallurgical
Student
Analytical
Chemist
Engineer
C. A. Edwards.
W. Whiteley.
W. E. Thorney-
croft.
H. D. Smith.
Summers Hunter.
H. J. Young.
A. Barr.
J. Steven.
H. H. A. Greer.
Annual General Meeting
29
Name.
Address.
Qualifications.
Proposers.
Page, Arthiir
Reginald
Sutton, Hubert,
.Sc.
Wukinson, Isaac
63 Walford Road,
Birmingham
The Firs, Reading
Road, S. Farn-
borough, Hants
550 Knutsford
Road, Warring-
ton, Lanes.
Metallurgical
Chemist
Research Student
Science Student
F. Lantsberry.
F. Johnson.
A. Spittle.
C. A. Edwards.
W. Whitcley.
W. E. Thorncy-
croft.
A. G. G. Gwyer.
C. A. Edwards.
J. E. Thomey-
croft.
Election of Auditor.
The President said that the next business ■v\as to elect an
auditor for the year 1918, but before proposing the election he
would like to ask the meeting to thank very heartily Mr. G. G.
Poppleton, who had acted as Honorary Auditor of the Institute
since its foundation ten years ago. The work involved was very
considerable, and it had been done with admirable precision, and
he was sure the members were very grateful to Mr. Poppleton
for acting as Honorary Auditor. He would propose that Mr.
Poppleton be re-elected as auditor for the current year.
Mr. J. Dewrance, Member of Council, in seconding the motion,
said that at the present time auditors were so very busy that it
was really exceptionally good of Mr. Poppleton to undertake
the work.
The President said as it was a matter for the members he
had to ask whether any member desired to nominate anyone
else as auditor.
There being no nominations, the motion was put, and was
carried unanimously.
New President.
The President said the last item on the Agenda was the
induction of the new President, Professor Carpenter. Professor
Carpenter might be the new President, but he was not new to the
80 Annual General Meeting
members in any other sense. He had been a member of the
Institute from the beginning, and had been one of the most
enthusiastic and active promoters of the Institute from its in-
ception. He had shown his interest steadily all through the
years by the reading of papers and by taking part in committees,
and he had played an important part in the organization of the
Corrosion Committee as Chairman, and had done a great deal
of work. Latterly he had taken a very great interest in the
committees which had been formed for the increase of member-
ship, and the results of the work of those committees had been
already commented upon. He had also done a ver}^ useful
work — often, perhaps, unconsciously to himself — in that great
work of co-operation to which reference had been made. In the
interests with which he (the speaker) had been connected, he
had quite frequently come across Professor Carpenter as a kind
of essential pivot in matters metallurgical in connection with
Government departments. His position in those departments
had been one of steadily increasing confidence, and department
after department had been prepared to accept his opinion, and
eager to have his advice. For the Board of Inventions and
Research at the Admiralty he had done exceedingly useful work.
In the Chemical Trench Warfare Department he had been called
upon time after time to give advice and help. Yet he had found
time during the past year to contribute to the literary side of
metallurgy ; everyone must have read his articles in " Nature "
on the wide international bearing of metallurgical questions with
the deepest interest and the greatest satisfaction. In his recent
lectures at the Society of Arts on " The Metallurgy of Copper "
he had really made almost a new departure in that kind of work.
In electing Dr. Carpenter as its President the Institute of Metals
was not alone in doing honour to him as a distinguished man of
science both pure and applied, for the Council of the Eoyal Society
had unanimously selected him as one of the fifteen new FeUows.
In the matter of congratulation it might be that the Institute
would equally congratulate the Eoyal Society on the accession
to it of a very important man of science, and Dr. Carpenter
himself on his election. It was now his very great pleasure to
ask Professor Carpenter to take the Presidential Chair as the new
President of the Institute.
Annual General Meeting 31
[Sir George Bbilby then vacated the Chair, which was taken
by Professor Carpenter amid acclamation.]
Sir Thomas Kose, D.Sc, Vice-President, said that it gave him
very much pleasure to ask the members of the Institute to pass a
hearty vote of thanks to the retiring President, Sir George Beilby,
for his valuable services during his term of office. He con-
sidered that the Institute might think itself extremely fortunate
in having had such an eminent President during the last two years.
Sir George Beilby was in the happy position of representing almost
equally well all sections of membership. His term of office had
been one of great opportunities for the Institute, and in his guid-
ance of affairs he had shown all the wisdom and tact and skill
that was expected of him, with the result that their opportunities
had been turned to full account. It was not surprising, therefore,
that the Institute had increased mightily in general esteem and
in numbers. It had been very fortunate for the members that
Sir George Beilby, following his connection with the Trench War-
fare Supply Department, had held the dual position of President
of the Institute and Chairman of the Fuel Research Board, which
was cormected with the Research Department. Sir George was
also a member of the Advisory Council to the Privy Council
Committee on Scientific and Industrial Research, a body with
which the Institute, through its Corrosion Research Committee,
was closely associated. He thought it possible that some small
part of the interest that Sir George had felt in promoting the
discussion on Metal Melting last year — one of their chief activities
of the year — was due to the hope of obtaining some information
from the members of the Institute which might be of use to him
in his capacity as Chairman of the Board. If there were any such
idea in Sir George's mind, he could only hope he was half as well
pleased with the Institute as the Institute had always been with
his conduct of affairs in the Chair. He had very much pleasure
in formally proposing that the best thanks of the meeting be
accorded to Sir George Beilby for his valuable services during
hig Presidency of the Institute.
Dr. R. S. HuTTON, Member of Council, said that it scarcely
needed many words of his to second the resolution. The
32 Annual General Meeting
o
members fully appreciated their good fortune in having had Sir
George Beilby as President. He had in every way successfully
and most tactfulh' guided the Institute through two difficult years.
The fact that the membership had been raised during this period
by nearly 50 per cent, was in large measure due to his personal
influence and to the help he had given in raising the standing
of the Institute and the appreciation of its work by Government
departments.
In particular, members would bear in mind what Sir George
had done for them in two directions. Firstly, in connection
with the Privy Council Eesearch Committee, especially by his
helpful influence in the development of the marvellously suc-
cessful Corrosion Eesearch Committee — a committee whose
reports had in recent years been such a feature of the meetings.
Secondly, in introducing the Discussion by the Institute of the
important subject of Fuel Economy, which had proved to
be of such great interest to a large number of new and old
members.
The resolution of thanks was then put and was carried
by acclamation.
Sir George Beilby, in responding, said he thought that on
an occasion of that kind probably the less one said the better.
He felt very deeply the kind thoughts that were in the minds
of the m.embers, and the kind expression they had given to those
thoughts. As one became older one depended more and more
upon human sympathy and human friendship — that was one of
the lessons of age — and he was bound to say that in his associa-
tion with the Council of the Institute of Metals, and wdth the
members, he had felt it a great privilege to bo brought in touch
with so many active and friendly minds, and with so much real
human sympathy. The kind expression that had been given to
that sympathy that evening he should take away with him with
the most grateful feeling. He should like to have made a few re-
marks on what had been said by the proposer and seconder, but
he believed he should most meet the wishes of the meeting if he
immediately made way for his successor, because everj^one was
most eager to hear what the new President had to say. He
would therefore confine himself to saying that any work he had
Annual General Meeting 33
done had been very small compared to the work done by mem-
bers of the Council, by the committees, and by Mr. Shaw Scott
and hid staff. He should like to say how grateful he was to them,
and how heartily he thanked them for their co-operation during
his two years of office.
The President then delivered his inaugural address (see
pp. 37-64), at the conclusion of which —
Engineer Vice-Admiral Sir George Goodwin, K.C.B., Member
of Council, said a very pleasant duty had fallen to his lot,
and that was to propose a vote of thanks to the President for
the admirable address that he had given. The members
ought to be very grateful indeed to the President for this
address, especially when it was realized what little time
he had to spare. As Sir George Beilby had already said,
Dr. Carpenter was a man of many activities in various direc-
tions, and it was difficult to see how he found time to do all
the work that he had to do. As a member of the Corrosion
Eesearch Committee he could testify to the great amount of
useful work that Professor Carpenter did there. He thought it
was due very largely to the way in which he managed the dis-
cussions, his wide knowledge, bis geniality, and his extreme
tactfulness, that the Committee was achieving such a large mea-
sure of success. But his work did not stop with the Committee ;
the Navy was brought a good deal into touch with it. The
Navy was intimately interested in the work that the Corrosion
Committee was doing — especially in the matter of the corrosion
of condenser tubes. He had recently been associated with the
President in other investigations, including some very important
ones connected with propeller material. That work required
high scientific knowledge and was carried out with great skill,
and the manner in which he had dealt with it had earned great
appreciation in, and had been of considerable value to, the Navy.
Although he felt that he had not been justly dealt with by the
previous speakers, who had already said much that he had in-
tended to say, there was one thing in which he would yield to
no one, and that was the sincerity with which he wished Professor
Carpenter a successful term of office as President of the Institute,
VOL XIX. D
34 Annual General Meeting
and he asked the members to accord him a hearty vote of thanks
for his instructive and interesting address.
Professor C. A. Edwards, D.Sc, Member of Council, said that
ho was delighted to have the privilege of seconding the vote of
thanks to Professor Carpenter for his very able, instructive, and
fruitful address. He felt that the Institute was to be congratu-
lated in possessing Professor Carpenter as its President, and in
having the opportunity of listening to such an extremely well-
thought-out address, dealing with what was an important subject.
He felt sure that Professor Carpenter would discharge the duties
which were attached to his office with the same care and attention
that the able Presidents who had held the position in the past
had done. He possessed all the qualities that were necessar}'-
to carry on successfully the high traditions of the Institute, and
ho had no doubt that those high qualities would be successfully
utilized during his term of office. He could speak with special
authority on the matter, because he had had exceptional oppor-
tunities to study Professor Carpenter's character. He could
claim, he thought, to be Professor Carpenter's first student of
metallurgy, and in addition he had had the opportunity of working
with him for many years in other capacities, and during those
years, which were really very happy and very pleasant to look
back upon, be could not remember his ever undertaking any
work which he had not successfully carried out to a very satis-
factory conclusion. His great capacity for work, and the masterly
manner in which he grasped all essential details, made it quite
evident that be would be able to carry out all his arduous duties
with great success. Although it was not in order to discuss a
Presidential Address, yet there was one point which he should
like to emphasize, and that was the one Professor Carpenter had
mad e with regard to manufacturers not being too keen in expecting
quick returns from the investment they made in employing 3^oung
scientific men. That was a most important matter for them to
bear in mind. He had been through those difficulties, and could
appreciate what Professor Carpenter had in mind when he drew
attention to them. The most important thing from the manu-
facturer's point of view, and certainly from the young student'si,
point of view, was for the student to feel that he had the conf -
Annual General Meeting 35
dence of the manufacturer, and to know that he could work with
that confidence and without feeling any uncertainty with regard
to his position. As an old pupil of Dr. Carpenter's, he felt some
embarrassment in seconding the vote of thanks. To him it was
a great pleasure to see Professor Carpenter in the Chair that
evening, and he was sure the feeling was supported by all members
of the Society. In carrying the motion for the vote of thanks
the members would also add their heartj'^ congratulations to him
on his recent election to the Eoyal Society.
The resolution of thanks was then put to the meeting by
Sir George Goodwin and carried ^vith acclamation.
The President said it was a great pleasure to him to respond
to a vote of thanks wh'ch had been moved so genially and felici-
tously by Admiral Sir George Goodwin, seconded by bis very old
friend, Professor Edwards, and carried so heartily by the members.
With regard to what Sir George Goodwin had been good enough
to say, and also what Professor Edwards had said, he confessed
that he hardly recognized himself in the almost too perfect char-
acter that had been presented, and he was relieved to r-^alize that
some of the members knew him too well to accept it all as being
true. None the less did he thank the speakers heartily for their
goodwill. Hb should like to dwell for a moment on his association
with Sir George Goodwin in the work they had been privileged
to do together. The Navy was a silent Service, but not quite so
silent as he had thought — he should never have dared to mention
the word " propeller " if the Admiral had not mentioned it,
but there w^as no harm now in his saying that the investigation
alluded to proved to be a long and very interesting one, and be
was very glad it had produced some results of practical importance.
j Incidentally it had been a great pleasure to him to be associated
' with one who was so typical of the finest qualities of the oflQceis
j of the British Navy. The Admiral was always serene, cheerful,
I master of himself, and never at a loss even when things were
apparently not going too well ; he had that good humour and
I resourcefulness which always carried the British Navy through.
] With regard to Professor Edwards, he had been associated with
J him for thirteen years. Professor Edwards came to assist him
^ with the work of the Eighth Alloys Eeport, and after that had
36 Annual General Meeting
been finished and he "went to the University of Manchester, the
first thing he did was to get Professor Edwards to follow him
there. Since then they had been associated in many pieces of
work, and this had been a great happiness to him. In conclusion,
he thanked the members very much indeed for the kind way in
which they had received the vote of thanks, and assured them
that it would be his best endeavour to advance the welfare and
interests of the Institute during his presidential year.
The meeting then adjourned.
SECOND DAY'S PEOCEEDINGS.
Thursday March, 14, 1918.
The President took the Chair at the adjourned meeting at 4 p.m.
The following communications were then presented, abstracts
being given by the authors except in the case of the Notes :
Mr. J. Neill Geeenwood, M.Sc. (Manchester), on " The Relationship between
Hardness and Constitution in the Copper-rich Aluminium-Copper Alloys.'
Mr. H. Whitakeb, M.Sc. (Manchester), and Mr. H. Rix (Manchester), on
"Aluminium Bronze Die Casting."
I Dr.[G. H. GuLLrv'ER (London), Note " On Grain Size."
Mr.' Owen Wm. Ellis, M.Sc. (London), Note on " Lead-Tin- Antimony]
"Alloys."
Profes.sor H.' C. |H. Carpenter, M.A., Ph.D., A.R.S.M., (London), and
Miss C. F.' Elam (London) on "An Investigation on Unsound
Ca.stings of Admiralty Bronze (88 : 10 : 2) : Its Cause and the Remedy.'
Mr. R. J. Anderson, B.Sc. (Cleveland, Ohio, U.S.A.), Note " On the Annealing
of Aluminium."
Each of the papers w^as discussed, and subsequent to the dis-
cussion the President proposed to each author a vote of thanks,
which was carried by acclamation.
The proceedings terminated at 9.30 p.m., with a vote of thanks j
to the Chemical Society for permitting the use of the Society's |
rooms for the purpose of holding the meeting.
Presidential Address 37
PRESIDENTIAL ADDRESS.*
By Professor H. C. H. CARPENTER, M.A., Ph.D., Assoc.R.S.M.
Scarcely more than ten years ago — the exact date was
February 8, 1908 — about a dozen men met in a solicitor's room
in the City of Manchester to discuss the possibiHty of founding
an institute for the purpose of advancing the scientific and
technical study of the engineering side of non-ferrous metallurgy
in this country. The impetus to this meeting had been given by
a letter from Mr. Eobertson of Bedford to Engineen7ig . Many
of us, I imagine, had long felt the great need for the existence of
an institute which should endeavour to do for the non-ferrous
metals what the Iron and Steel Institute has done for iron and
steel, but it is right we should acknowledge that the jfirst step
taken towards its realization was Mr. Eobertson's letter. To-day
in addressing, as I now have the honour to do, the Institute of
Metals, which has a membership of more than 900 spread far and
wide over the earth, 9, record of most distinguished Past-Presidents,
and a Journal which takes its place among the best metallurgical
publications of the day, it is impossible to avoid the reflection
that in 1908 we were more than ready for the establishment of
such an Institute, and that Mr. Eobertson's letter acted with the
swiftness of a crystal placed in a supersaturated liquid in giving
the impetus to its formation and wonderfully rapid growth.
Young though we are, however, death has removed several
who laboured zealously for the Institute in the early days, whose
services should always be kept in grateful recollection. May I
recall to you two names ? The first is that of Sir William White,
our first President. It was he, I remember, who, when we con-
sulted him about the organization of the new Institute, insisted
on the necessity of having represented on the Council, and in
approximately equal proportions, those who manufactured metals
and alloys, those who used them, and those who studied their
Scientific properties in laboratories and research institutions.
♦ Delivered at the Annual General Meeting, London, March 13, 1918.
38 Presidential Address
In taking this stand Sir William White made himself responsible
for a policy which I believe more than anything else has conduced
to the rapid, fiuitful, and harmonious development of the Institute
and has given it its special character. I would like to put the
matter somewhat colloquially by saying that we have fair play
as between our various elements, and I think I may add that we
are in consequence a happy family. Most of us — indeed I hope
I may say all of us — who are actively in touch mth the work of
the Institute must, I think, feel how much we owe to the inter-
course we have with members representing other aspects of
metallurgy than those with which we have normal daily contact
in our o^^^l work. At any rate, speaking for myself, I gladly
testify to the educational benefit I have received from meeting
and discussing metallurgical problems with my fellow-members
in this way, and I think there are many others who would gladly
bear the same testimony. In my opinion, therefore, it would be
difficult to overestimate the importance of the policy for whose
adoption Sir William AMiite more than anyone else was responsible.
His great services to us rendered during his two memorable
years of Presidency are still fresh in our recollection, and I am,
I think, sure of your agreement when I say that by reason of his
ripe experience, rare judgment, scrupulous fairness, and genuine
sympathy with all branches of our work j he constituted as nearly
perfect a President as we could have had.
My second name is perhaps not so familiar to you. It is that
of Mr. W. H. Johnson of Manchester. I was privileged to act
with him as co-Hon. Secretary to the Institute in the first days
of its existence. He took the chair at the inaugural meeting in
Manchester to which I have already referred. I do not think
there is anyone who can testify with as much knowledge as I
possess to the devotion and zeal with which he served the Institute
for the first six years of its existence, up to the time of his death
four years ago. During much of this period he was in failing
health, but it never prevented him from showing his deep interest
in the welfare of our body, and he laboured with unstinted effort
up to the end. He did not live to be, what he had so richly earned,
one of our Presidents, and I think therefore that his services to
tlie Institute so unselfishly rendered should be held in special
remembrance.
The Institute has been splendidly served by the Presidents
Presidential Address B9
who succeeded Sir William White. Let me just mention their
names in chronological sequence : Sir Gerard Muntz, Professor
Gowland, Professor Huntington, Sir Henry Oram, and Sir George
Beilby, all of them men greatly esteemed in their professions,
who, each in his own particular way, and representing in the
aggregate our three main types of membership, has contributed
notably to the advancement of the welfare of our body and helped
to bring it to its present position. May I also add a few words
of appreciation with regard to the services of our Secretary, Mr.
G. Shaw Scott ? When the growth of the Institute had reached a
point at which it became impossible for the Hon. Secretaries to
cope with all its requirements — which it did in the late summer
of 1908 — the Council decided to appoint a paid Secretary, who
should give the greater part of his time to the work. I remember
that we advertised and received more than 100 applications for the
post. It fell to me to go through them and make a short list for
submission to the President, and I recall doing this on my summer
holiday in a little inn in one of the remote islands of the Hebrides,
where it required something of a mental effort to realize that there
was such a thing as metallurgy at all. Mr. Shaw Scott was placed
on the short list of six, and the President's choice fell on him. It
was the right decision. He has served us faithfully and with
remarkable zeal and good^\i^, and to him much credit is due for
the favourable position in which we find ourselves to-day. Up
till the end of last year, w^hile giving us the greater part of his
time, he was also engaged in technical journalistic work, from
which the Institute as well as he himself have derived distinct
benefit. I am very glad, however, to be able to inform you that
as from the beginning of this year the Institute has commanded
his whole-time services, and we anticipate that the results of the
new arrangement into which we have entered will be very bene-
ficial both to him and to us.
I desire to thank you for the great honour paid and confidence
reposed in me, in your choice of myself as your President. It
is not easy— in fact, it is impossible — for me to say how highly
I prize this. I must plead guilty to having had a certain amount to
do with the formation and development of the Institute, and I
gladly take this opportunity of saying that no work I have ever
been privileged to do has given me greater satisfaction or appeared
to me to be more worth doing than my small share in bringing
40 Presidential Address
about our present position. May I add that I desire to do every-
thing in my power to maintain the dignity and advance the
welfare of the Institute to which we are so much attached ? In
attempting to do this I know that I may rely on the loyalty
and active support, not only of the Council, but of the members
as a whole.
Before passing to the main subject of my address, I should
like to allude to three features of the life of the Institute which
appear to me to merit comment.
In the first place, if I were asked — and I sometimes am asked —
to justify our existence to-day by a single test, I think I should
point to the sales of our Journal as my answer. I submit that
this is a good practical test. People do not buy technical journals
unless they are worth buying, and our Journal is not a cheap one.
Eemember that we are a young Institute, and from the beginning
we have published two volumes each year averaging about 300
pages each. Eemember, too, that each member of the Institute
gets his or her Journal included in the subscription, that various
Libraries, Universities, and Technical Colleges receive presenta-
tion copies, and that we exchange with other Journals. In the
year 1910-11 — our year dates from July 1 — the sales amounted
to £124. This was not quite two years after our foundation.
In the next year they rose to £160, then to £216, and then to £225
in the succeeding years. In the year 1914-15, in which the war
broke out, there was a drop to £182. The next year the sales
amounted to £320. Last year they reached £415, and this year,
which will not be completed until June 30, they are even higher
than in any corresponding period to date.* You will see, there-
fore, that not only was there an increasing demand for the Journal
before the war, but also that the metallurgical requirements of
the latter and the numerous problems with which manufacturers
and users of non-ferrous metals and alloys in this country and
those of its Allies are now faced have evidently created a demand
for the kind of knowledge which our Journal famishes, an J I beg
you to note that this demand is still increasing. In other words —
and if my interpretation is justified — it has been found that the
Journal is able to supply information which has been of direct
♦ Tho sale* in eight months of our present 'year already exceed those in the lehcle of last
year.
Presidential Address 41
practical value in the national crisis, and I think, and certainly
hope, that this will continue to be the case in the years which
follow the establishment of peace, when economic competition
in the world's markets is likely to be severe and will demand the
highest technical efficiency of which we are capable. The demand
for our Journal in the United States of America is especially note-
worthy, and points a moral for us which I need not labour. It
is all the more remarkable in that that country quickly followed
our lead in establishing a corresponding Institute known as the
American Institute of Metals which publishes its own Journal.
As yet, we are the only two countries who support a technical
Institute devoted solely to the study of non-ferrous metals and
alloys.
My next comment refers to our membership. The figures
on December 31 of each year since our foundation in June 1908
are as follows :
Year.
Total Membership
1908
355
1909
505
1910
551
1911
686
1912
606
1913
626
1914
645
1915
640
1916
660
1917
88S
You will notice that we started with what I may call an original
membership of 355, and that in the two years succeeding 1908
we averaged a net annual increase of just about 100. In the next
six years our total increase, however, was only 109, corresponding
to an average annual increase of a paltry 18. In 1917, however,
a net increase of no less than 228 new members took place. Thi?
striking augmentation of our number after a lengthy period of
only gradual increase deserves our attention and examination.
The comparatively rapid growth of the Institute in the first thirty
months of our existence was highly gratifying, and was due to
the energy, zeal, and enthusiasm which animated those who
launched the new enterprise. The labours which produced this
result were, however, the work of individuals who canvassed
vigorously each in their own way among their personal friends,
and I may be allowed to refer to the successful efforts of Sir
42 Presidential Address
William White, Vice-Admiral Sir Henry Oram, and Mr. J. T.
Milton, which have as their result the fact that we number among
our members a remarkable proportion of marine engineers and
shipbuilders. The succeeding six lean years, however, demon-
strated conclusively that, if a satisfactory net increase of member-
ship was to be regained, something more systematic in the way of
an effort, which should be directed by the Institute itself , must be
prepared for and launched. It is the signal service of Mr. G. B.
Brook of Sheffield to. have shown, in the early months of last year,
what could be done by the pertinacious canvassing of a particular
district. I think it is probably the case that his position as
inspector under the Ministry of Munitions gave him a certain
power in this direction which would othei-wise have been absent.
Nevertheless, after making full allowance for this, it must be
conceded, I think, that it was a remarkable result for himself
and his co-workers to achieve that, at the March ballot for new
members, just over one-half the total — 45 out of 88 — came from
the Sheffield district in which they had worked. This result was
just the demonstration the Council needed that, if only they set
to work in the right way, other districts could be made to con-
tribute increases, I do not say of the same magnitude, but at any
rate of a like character. Accordingly, early in May an "Increase
of Membership " Committee was set up. This Committee set
to work without delay, and during the summer got in touch with
our Birmingham friends who have for several years had a local
section. They took the matter up vigorously, and with Mr.
Evered as Chairman and Mr. Bill-Gozzard as Local Secretary, a
successful campaign was prosecuted which produced no less than
83 new members. These efforts concentrated in the Sheffield
and Birmingham districts — both of them important centres of
the non-ferrous metal industries — have produced more than half
the great increase of membership which occurred in 1917. I
am glad to say that similar movements have more recently still
been organized, at the suggestion of the above Committee, on the
one hand in Glasgow and the West of Scotland, and on the other
hand in Manchester and South-West Lancashire, and we hope
for considerable accessions of new members from these sources.
In due course I hope that similar campaigns will be initiated in
the Newcastle district, in the south-west (including Bristol and
Presidential Address 43
South Wales), and, though it is much our largest centre, in London
itself. All of these will, I am convinced, give a good return to
properly directed effort.
Anyone familiar vdih. our Journal must have been struck
with the fact that copper and its alloys figure much more
frequently in our pages than any other metal, and this no doubt
corresponds to a preponderance in the number of our members
who are engaged either in manufacturing or using this metal and
its alloys, and to the fact that these have always been the most
important industrial non-ferrous materials.
But, as I have ventured to point out in a recent paper, the
position of copper is being seriously challenged by aluminium and
its alloys in many practical applications, while there are numerous
other directions in which it is the only metal which can be used.
Then there is nickel and its important industrial alloys, zinc and
its various alloys, together with tin, lead, antimony, and their
alloys — all of them metals produced in comparatively large
quantities. I may be quite mistaken, but I venture to doubt
whether any of these metals is represented in our membership
to an extent which corresponds to its practical importance. If
this is the case we ought to take steps to remedy the deficiency,
and if this is done I think it will come to have a beneficial effect
both on the Institute as such and on ourselves in increasing our
financial stability and broadening our knowledge of metals. My
owTi view, taking everything into consideration, is that we ought
to be able in due time to raise the membership of the Institute to
at least 1500, and to maintain it there. I am not going to prophesy,
but I think it can and will be done.
My third point has to do with the work of the Corrosion
Research Committee. As no doubt most of you are aware, the
Council of the Institute, not quite two years after its foundation,
f5et its hand to attempt the solution of one of the most pertinacious
difficulties and perplexing problems that confronted then — and
still confronts — the users of non-ferrous alloys, viz. the corrosion
of brass marine condenser tubes by salt water. I think it is
worth recalling this to you, because, so far as I know, no teclmical
society has at so early a stage of its existence made itself responsible
for, and in a sense staked its reputation upon, the solution of
a problem of wide practical interest. But we had round the
44 Presidential Address
Council table the men who made the tubes and the men who
used them — both equally anxious for success — and in addition
laboratory workers who could advise as to the methods by which
the problem should be attacked ; and w^e decided that the attempt
could and should be made. Our resources were slender. We
started a fund and invited subscriptions. What is more, we got
them. At least we got enough to enable us to begin the investiga-
tion. We set up a Corrosion Cormnittee. Dr. Bengough agreed
to act as our investigator and to give his services in his spare time.
The University of Liverpool gave the laboratory accommodation
and made us a grant of £50 per annum tow^ards our costs. And
the makers gave us the tubes. The only thing that had to be
paid for was the small-scale condenser plant. Truly, if ever an
investigation was begun with an unlimited fund of energy
and goodwill, the slenderest of financial resources, and all
misgivings as to ultimate success kept resolutely in the back-
ground, this was so begun.
WTiat happened ? Dr. Bengough agreed, in the first place, to
prepare a resume of the literature on the corrosion of condenser
tubes, which was already considerable. His main conclusion,
embodied in the first report to the Committee, was that none of
the existing views on the subject could be regarded as in any way
established, that the evidence was conflicting in eveiy case, that
nothing could be taken for granted, and that he must start at
the very beginning. Undoubtedly the ideal way of tackling the
problem would have been to investigate the corrosion of the
pure metals concerned, viz. copper and zinc, in the first instance,
and to endeavour to explain how and w^hy corrosion starts at any
given place in such metals. This is where our slender financial
resources imposed on us a di£ferentpolicy,however,and a beginning
was made on condenser tube alloy which, although it contains
the tw^o metals, is nevertheless theoretically a one-phase system,
and it was hoped that this compromise would work. That only
a partial success was achieved the events of the next four years
proved ; for, although in this period two reports were published,
and contained much valuable information, neither of them went
to the root of the matter, nor could they do so on account of the
fact that a problem with too many variables had been attacked
before determining the effect of each under appropriate conditions.
Presidential Address 45
That our work was by no means fmitless, however, is shown by
a letter we received lately from an American firm, who tell us
that they are specialists in condenser tube manufacture, and have
had forty-five years' experience in the casting and working of
brass. They say :
'* It has been our good fortune to secure a copy of the second
report to the Corrosion Committee of the Institute of Metals.
This is not only most interesting, but also very instructive and
complete. It has given the engineering world the best data and
information on causes and prevention of failure in condenser
tubes of anything that has been published up to the present time.
To the men who made the investigation and compiled the report
is due the heartiest congratulations of the w^orld on their work.
Ihrough them the Institute of Metals has been brought closer to
the manufacturer and the engineer, and by such work as this the
Institute will gain the entire confidence of practical men of the
world, who will look to them more and more for solutions of their
troubles and problems."
In 1916 the work of the Committee was, at the request of our
Council, aided by the Advisory Council for Scientific and Industrial
Eesearch, and a substantial financial grant from the Treasury
made. In consequence of this we have been able to arrange for
the research to be carried out under conditions much more nearly
approaching the ideal. Since the summer of 1916, Drs. Bengough
and Hudson have devoted their whole time to the investigation
of the problem — and quite recently Miss Goodwin has been added
to their staff.
A laboratory specially designed and equipped for the work
has been installed in the metallurgical department of the Eoyal
School of Mines, and as a result of a kind offer by Mr. Christie
our experimental plant has been removed from Liverpool to the
Southwick Power Station at Brighton, and is being run under
strictly practical conditions. Most important of all, it has been
possible for the Committee to arrange that the problem should
be attacked in the laboratory ab initio with pure metals corrod-
ing under the simplest conditions, and the sound fruits of this
policy wiU, I think,' be found to have ripened when the results of
this investigation come to be published. Our investigators are
engaged on the fundamental task of laying the foundations of a
46 Presidential Address
theory of corrosion which shall be in harmony with, and as far
as possible explain, all the observed facts, and thus lead up to the
practical solution. It has turned out to be a case of " the longest
way round is the shortest way there."
It is the privilege of one who occupies such a position as has
fallen to my lot in the last twelve years to endeavour to serve
the needs of non-ferrous metallurgy in two main ways : (1) By
the execution and publication of research work ; (2) by the
training of students destined to take up technical positions in
metallurgical works. As regards the former, it is not my intention
to say anything to-day other than that such work is, for the
most part, essentially individualistic in its character. It is the
expression of a man's personality in creative work of a particular
kind. The function and application of such work is, I think, well
understood in our Institute, and of this the Journal, if nothing
else, is witness. The latter subject, however, receives very little
attention on the whole, and in my opinion much less than its
importance warrants. I venture therefore to use this opportunity
of asking your attention to a few observations on it that I propose
to make.
Non-ferrous metallurgy may be divided into two main parts
which are quite distinct and well defined. One begins where the
other ends. The first may be described as ore-treatment, and its
field of operations is the extraction of metals from their ores. In
other words, it is smelting. It may conveniently be regarded
as having fulfilled its function when a marketable metal or alloy
has been produced. With this side of metallurgy we, as an Insti-
tute, are not concerned. It is the province of our elder brother
■ — or is it sister ? — the Institution of Mining and Metallurgy.
The second includes the working up of the raw merchantable
products of the first by mechanical processes into a variety of
finished materials, the founding of alloys, their mechanical and
heat treatment, &c. On the whole, while I do not think that
there is any generally accepted designation for work of this some-
what composite character, the term metallurgical engineering
seems to me to encompass it with sufiicient accuracy. This is
the province which we, as an Institute, have entered into and
done our best to possess. We are, in fact, the youngest of the
Engineering Societies. That we are recognized as an Engineering
Presidential Address 47
Society is testified by the invitation extended us to participate
in the important Conference on Engineering Education held at
the Institution of Civil Engineers last October.
This being the case, let us consider briefly and in the broadest
possible way what we should aim at in the training of men
destined to occupy technical positions in works. You will, I
trust, recognize how fully I realize my own responsibility in this
matter, and how desirous I am of making myself a party to
any plan which has for its avowed object the providing of the
most appropriate education for such men.
The first point I wish to make — I do not know that I really
need make it, but I want to be so clear on the subject that
no misunderstanding is possible — is that the training, being by
definition for a technical profession, cannot be wholly undertaken
at a technical school or university ; that it must be of a twofold
character ; that the technical school or university has its part,
and no less certainly that the works itself has its part also. If
there are any who differ from me on this fundamental point, I
am afraid we must part company here. It is vital to my attitude
on the matter. If, however, as I hope, there is universal agree-
ment as to this, we can at once take a step which limits the ground
over which I desire to travel to-day, viz. we can seek to define the
scope of the two functions mentioned, and confine ourselves
mainly to a consideration of one of them. Let me therefore
attempt this. The function of the technical school or imiversity
to which intending metallurgists come from secondary or higher
grade schools is (1) to provide the necessary training in the
fundamental sciences, physics, mechanics, chemistry, physical
chemistry, mathematics, geology, and mineralogy, and this should
be done before any attempt is made to give any instruction at
all in any of the applied sciences. For these two years are
necessary. (2) On the above foundations should be raised the
structure of the knowledge of the principles of the applied sciences ;
fuel (including refractory materials), metallurgy, both ferrous
and non-ferrous, the strength of materials, power production,
and applied electricity. For these two more years will be needed.
(3) Every attempt should be made — and made as soon as the
students have reached the necessary standard — to get them into
the way of acquiring knowledge for themselves, of testing its
48 Presidential Address
reliability — and, generally speaking, to instil in them habits of
independence of mind, resourcefulness, and initiative. I doubt
whether the teacher at any educational institution of the kind
referred to can render a greater or more absolutely fundamental
service to the student who contemplates entering a works, than
to awaken and strengthen in him the capacity to acquire know-
ledge for himself, and to be able to judge when he has acquired
it, the precise degree of reliability attaching to it. Whatever
the circumstances with which such a man may be faced, and
however difficult it may be for him either to act or to give his
opinion w^hen called upon to do so in any given situation, if he
has this twofold quality — the power to acquire knowledge and
the capacity of estimating just how much weight should be
attached to it — ^he wall nearly always be about right, and he will
certainly never be far wrong. Both these qualities are really
indispensable — the one creative, the other destructive in its
operations. Each has its function ; neither is complete without
the other. The necessity for the former is self-evident ; but it
may be thought that I am unduly stressing the importance of
inculcating the habitual use of the critical faculty. May I there-
fore recall to you the words of one of the noblest and most success-
ful workers in applied science — I refer to Pasteur. Speaking
on the occasion of his seventieth birthday to colleagues and
pupils at the Institute which bears his name and w^as founded
in his honour, he used these memorable words, which have been
more helpful to me in my scientific and technical work than any
others that I can call to mind : " Cultivate the spirit of criticism.
By itself it is neither a generator of ideas nor a stimulus to great
things. Without it nothing will avail. With it will always
remain the last word."
To my mind, then, these three elements of training — a sound
and broad scientific foundation, an adequate superstructure of
knowledge of the principles of metallurgy and cognate branches
of the arts and the applied sciences, and the awakening and
development of the mental characteristics just touched upon —
are what a technical college or university should concentrate
upon. Less than this w'ould involve the omission of some essential
element of training, more than this it would be unwise to attempt,
for it could only be successful wdth students of unusually high
Presidential Address 49
ability, and they can always be relied upon to make good what-
ever their training. How can these aims best be achieved ? I
can, of course, only discuss the matter in general terms, and
in what follows may I ask you to remember that I am simply
; endeavouring to contribute something from my o-^-n experience
that may be worth stating.
Educational influences — using the term in a very broad
I sense — as a rule operate on the student in the following ways :
(1) By contact with his teachers ; (2) by contact with his fellow-
students, and (3) by the discipline of laboratory work and other
ways in which the essential principle is that he has to make the
efforts himself. Let me review these briefly.
No. 1 will no doubt at once suggest lectures, and these, though
they do not exhaust this category, are at any rate an important
feature of it. Are lectures really necessary ? To some, no doubt,
it may appear that as there are good text-books on the most
important aspects of metallurgy, and a vast number of original
papers, all that is required is to see that the student studies a
proper selection of these. The mere imparting of knowledge,
however, such as can be found in text-books, is not, in my opinion,
the function of a lecturer. If the student — ^particularly at the
beginning of his specific metallurgical training in the third year,
such as I have presupposed — could really master original papers,
and especially those dealing with intricate and disputed points
of theory, and if he could weigh the evidence as he reads, I should
agree that the case for lectures was very much weakened and
that their necessity was open to question. But this is just what
most students cannot do and what they require training in, and
from this point of view lectures constitute a valuable instrument
of education. In an hour's lecture it is possible to bring to a
focus a wealth of considerations bearing on some given point of
theory or practice, and thus to put before the student an aspect
of the subject which so far as I know cannot be presented in any
other way ; and if the lecturer is successful, he will have created
in the student's mind — I am, of course, assuming that the student
is a willing accomplice, a condition that does not always hold
good — a new point of view such as will cause him continually
to use his mind on it — in a word, that will make him think, that
rare and most precious of happenings. Once this habit is achieved
VOL KIX. E
50 Presidential Address
— sometimes it is never achieved — lectures do not require to con-
stitute so large a part of the student's education, and therefore
in his fourth year it should be possible to diminish them. In
this case they can advantageously be partly replaced by the less
formal colloquium in which the students themselves largely
take charge of the discussion of problems and important questions.
The value of this training in arousing habits of independence of
mind, criticism, and the exercise of judgment is so obvious as
to require no elaboration.
2. That students can and do educate one another is the
experience of any teacher who takes the trouble to obser^^e it.
This is obvious in a variety of ways, and certainly shows most
markedly in successive examination tests. The difference in
standard between succeeding years of men is sometimes astonish-
ing, and I have always found that the high standard years are
attributable to the influence of one or more students of unusual
ability who have raised the level of the remainder. I am not
suggesting that this is consciously done on their part^I do not
think it is. It occurs simply as the result of the normal inter-
course of men who are working together and competing against
one another for such a period as four years ; and I must say I
regard this as one of the most valuable results of the educational
system that we have.
3. Experimental work in the laboratory, if properly chosen
and carried out, is a most important — indeed an absolutely
essential — element in the training of metallurgical students. It
constitutes, in fact, from the point of view of the time taken, much
the largest part of the training. I have said it must be properly
chosen, because if it is to exercise its maximum educational effect,
either it must be related as closely as possible to the principles
enunciated in the lectures or the matters discussed in the colloquia ,
or it should be designed with at any rate some particular end in
view. There is, if I may say so, a tendency to make analytical
work too prominent a feature of laboratory training. The edu-
cational value of a training in accurate quantitative analytical
work I should be the first to iasist on, but analysis is seldom an
end in itself. It is a means to an end, and this is apt to be lost
sight of. And the fact that the view is held in many works that
the only thing a metallurgist who comes to them from a technical
Presidential Address 51
college or university can do is to analyze — and not always that — •
is a well-justified criticism that we teachers should take to heart
and do our best to remedy. What is required, in my opmion, is
a course of practical work so chosen as to exemplify and give
rigorous training, on the one hand,*in the principles of metallurgical
processes, and, on the other hand, the testing of metallurgical
theories. In such a course analytical methods have their due-
hut not more than their due — share, and the student gets into
the way of viewing analysis in its proper place and proportion.
Having regard to the requirements of such an institute as ours,
there is to-day an urgent Qeed to see that the training in physical
and physico-chemical methods of testing and investigation is the
very best that can be devised. Metallography, the testing of
materials, and chemical analysis are the handmaids of our industry,
and the r61e of the first named becomes more important every
year.
I have sketched, all too imperfectly and briefly, the broad
principles of metallurgical training such as, in my opinion, should
be given at educational institutions, and the underlying principles
of methods by which such instruction can advantageously be
given. I have said nothing as to the training that the student
should get in the works itself, and I propose to touch on this aspect
of the matter only very briefly, because here my responsibility
ends and that of the works begins. The few remarks I am going
to make are in the nature of an appeal to the management of the
works into which the students enter.
I think the most suitable period at which to link up the
training given at the educational institution with that of the
works is at the end of the student's third year at the former. By
this time he has had instruction in the fundamental sciences and
a year at his professional subject, and he should have acquired
something of the habits of judgment and independence of mind
upon which I have laid such stress. He ought therefore to be
ready to appreciate what he sees and get some value out of it.
He has a three months' vacation, and this time can most
advantageously be spent at a works. There is generally little or
no difficulty about arranging this, and my own students do it
regularly. They then return to their fourth and last year of
gtudy at the educational institution with, at any rate, some idea
62 Presidential Address
of the kind of work that awaits them at the works, and this should
give a reality particularly to the character of the practical work
in this year which would otherwise be less vivid. It must be
emphasized, however, that the three months' period referred to
cannot do more than familiarize hi a very general way the student
with the nature of works practice. The actual training in this
cannot, however, begin until after the end of the fourth year, and
this is the point at which I wish to make my appeal. The students
who leave us, though they have all had the same training, are men
each with his own special character and mental endowment. It
is the function of the works they entei^to find out what special
aptitudes each man has, so that at the end of his period of training
in their practice he can be entrusted with work which will make
the very best of him. Give him, therefore, /or a sufficient time
an opportunity of acquainting himself with eveiy side of that
practice — not the laboratory methods only, but the practice of
each of the operating departments. Give Mm time to find Ms
feet and to acquire the worhs atmosphere, and let him have
adequate opportunities of obtaining information on any details
he wants as to the why and wherefore of any given operation
he sees but does not completely understand. Do not stint this
period, for it is difficult to over-estimate its importance and possible
return to you in years to come. A discerning management will
have little difficulty in judging how they can best utilize the
services of such a man after this probationary period, during
which he should be paid at any rate a living wage.
Some of these men may develop special aptitudes in connection
with the requirements of the operating departments. They may
— and this is the most vital element of training that no educational
institution can ever give, but only the works itself — be found
capable of working with and getting the best out of the operating
staff and the labour in these departments, which can only be
done by the exercise of human sympathy and insight in addition
to technical knowledge. In a word, their interest will be the
practical operations of the plant rather than the scientific processes
which underlie them. Such men are not very common, and they
are worth finding out, for they are quite capable of producing
reforms in works practice.
Others — in spite of their prolonged training — may never
develop sufficient independence of mind or confidence in their
Presidential Address 53
powers to enable them to take up a position to which much
responsibility attaches, whether in the operating departments
or the testing laboratory, but they will usually work well and
faithfully under direction and produce results upon which reliance
can be placed. Do not despise them. They fill a r61e which
brilliant men would find irksome. They do work which has to
be done, and are content to do it.
Others again — and these are usually the men of the greatest
•originality and imbued with the desire of improving upon
•existing processes used in the works by discovering new methods
— find the most suitable exercise of their faculties in the labor-
atories where facilities for research work are to be found.
These men are to be encouraged, even if results are slow in
coming. Some of the leading works of so eminently practical
a nation as our brothers in the United States of America
have recognized, not only the importance, but the necessity of
establishing laboratories where work of this kind can be carried
out, and where the theoretical basis of each works operation is
investigated more fundamentally than can be done even in a
university or technical school, and where no practical results
are looked for under a period of from five to ten years. Men who
are capable of doing this work are rare indeed, but most of all
are they worth discovering and employing in such labours. They
are the men who, if I may apply a striking phrase recently uttered
by the President of the Eoyal Society, will produce not merely
a reform in your practice, but a revolution.
I think you would not wish me to close my remarks without
making some reference to the war. Although two years have
elapsed since my predecessor delivered his Presidential Address,
the terrible conflict still rages, and indeed has become, since he
Bpoke, a world struggle. What its end will be, and when, no one
even now can judge, much less tell. It is fitting that we should
recall with special gratitude and reverence the names of those
of our own members who in this period have given up their lives
in the battle of right against wrong, of truth against falsehood
of law against frightfulness, in order that, in President Wilson's
ever memorable words, the world may be made " safe for
democracy." The names are: Engineer Lieut. K. Grazebrook,
the Et. Hon. Lord Guernsey, Captain W. Morton Johnson,
Engineer Commander E. Main, Captain E. W. Narracott. and
54 Pfesidential Address
Engineer-Captain C. S. Taylor. I would like to put the matter
even more personally, and say that these brothers of ours have
died for you and me, and that their altruism lays on us the duty
and privilege in our own personal lives of seeing to it that we will
be worthy of their sacrifice.
As an Institute it has been our privilege to render, I think
I may say, a not inconsiderable service of work for the Govern-
ment. It has been willingly and cheerfully done by our members,
many of whom have been consulted in connection with war
problems and difficulties. Ours is a field of knowledge and enter-
prise which is directly applied in the prosecution of the war.
Judged from this point of view, our birth a decade since may
justly be regarded as not having been without its importance,
though none of those, I imagine, who took part in the proceedings
'of that time had in mind the probability of our energies being put
•to such use.
I should like, however — and on this note I wish to finish my
-address — to recall to you a feature of our organization which not
<only has no relation to the waging of war, but may one day aid
in preventing its occurrence at all. I refer to the fact that we
organized ourselves from the beginning as an Institute on an
international basis. Thereby we gave a definite pledge to man-
kind that in our judgment peace, and not war, was the normal
relation between the nations of this earth . Before long we counted
Bmong our members metallurgists in every country in Europe in
which the art is practised, and even in some where it is absent.
We were in the habit of meeting them in friendly scientific inter-
course both in this country and on the Continent. Less than a
year before the war we held our autumn meeting in that little
country which has paid so terrible a price for choosing death,
torture, and outrage rather than dishonour, and in doing so has
furnished the most superb spectacle of devotion to heroic national
ideals that the world has ever seen. Are we not entitled to hope
that after the return of peace, small though we are in numbers,
and probably but little known outside the technical public and
technical press, our act of faith constituted one of the nuclei from
which the league of nations will ultimately ciystallize in a stable
iind enduring form ?
Creenwood : Aluminium^Copper Alloys 55
THE CONSTITUTION OF THE COPPER RICH
ALUMINIUM-COPPER ALLOYS.*
PART I.
RELATIONSHIP OF HARDNESS TO CONSTITUTION.
By J. NEILL GREENWOOD, M.Sc. (Manchester).
INTRODUCTION.
The following research has been conducted almost entirely in the
Metallurgical Department of the Victoria University (Manchester),
and before giving any description of it, the author wishes to
express his thanks to Professor C. A. Edwards, both for suggest-
ing the subject — the hardness of aluminium-copper alloys — and
also for the interesting and fruitful discussions which have arisen
whilst the work has been in progress.
At an early stage it became evident that the subject was
more complicated than seemed at first sight, and the present
paper is only a preliminary to the research which was actually
suggested. The original idea has now been fitted into a series of
investigations, by means of which the author hopes, ultimately,
to arrive at a definite idea of the constitution of the various
solid solutions composing the entire series of copper-aluminium
alloys.
Summary of Previous Work dealing with this
Subject.
Tlie existing data regarding the hardness of Al-Cu alloys is
of a very fragmentary nature. Owing to the great complexity
of the possible transformations, even in the copper rich alloys
(between 9 and 16 per cent. Al), hardness data, without either
* Bead at Annual General Meeting, London, March, 14, 1918.
56 Greenwood .' The Constitution of the Copper
a complete account of the heat treatment of the specimens, or
a description of the actual structure, are useless.
From the point of view of the present investigation, the only
previous work dealing with the more general aspects of the subject
is that by Carpenter and Edwards,* and by Curry.f (See Fig. 1.)
As regards the former, owing to the magnitude of the task of
investigating a complex series of alloys, such as those now under
consideration, it is obvious that on many points only a preliminary
survey can be made. This was the case with (a) the equilibrium
diagram of the Al-Cu alloys ; (&) the hardness tests. With
regard to (a), although most of the phases now recognized were
included in the diagram given in the Eighth Eeport, still the
actual transformation temperatures, as also the actual limits of
the phase areas, were not definitely fixed. As regards (fe), the
series of hardness tests made on the alloys as rolled obviously
make no pretence of correlating the hardness with the constitu-
tion, though they are valuable as a preliminary guide, since in
each case a photomicrograph of the structure is given. The
actual results will be discussed later.
Curry's work on the equilibrium diagram of these alloys forms
a valuable supplement to the data compiled by Carpenter and
Edwards. It is unfortunate, however, that there is no available
evidence for checking the conclusions contained in this paper.
The bare facts are given, but experimental conditions, thermal
curves, and photomicrographs are lacking. As a result of his
work, Curry f gives the following limits of existence of the a,
/3, and 7 solid solutions at several temperatures :
Table I.
Phase.
1000' C.
700' C.
SOOT.
a
7 or 5
iiil-8 per cent. Al
10-15 per cent.
16-17
nil-9 per cent. Al
11-5-13 per cent.
16-20
nil-9 per cent. Al ]
Unstable
16-21 per cent.
♦ " Eighth Report to the Alloys Research Committee," Journal of the Institute of Mecl inical
Engineers, 1907.
t Journal of Physical Chemistry, 1907.
X Andrew (Journal of the Institute of Metals, 1915, No. 1, vol. xiii. p. 251) has thown that
the 7 phase is only stable (between 13-5 to 16 per cent. Al) above 770° C; below this, the 5 phase
is stable. In the sequel this notation is adhered to, as being the most probable explanation
of the facts at present known.
Rich Aluminium-Copper Alloys
57
Although several cases have arisen during the present in-
vestigation to throw doubt on the accuracy of these limiting
values, time has not permitted a more complete survey of the
1000
Q
<^ 900
^eoo
"^
==^
-^
/
c
c
loc 1
1 "*" 1
\ \
^ /e
\
1
o 700
\
\ 1
1 +
/ ^
SOD
.
\
/
OL
+ s
Fia. 1. — Equilibrium Diagram for Al-Cu Alloys.
[After Carpenter and Edwards ; Curry ; and Andrew.]
equilibrium diagram. This is unfortunate, as it^either prevents,
or makes doubtful, certain deductions which might otherwise
have' been' made. Had this point been recognized earlier, the
logical course would have been to fix accurately the limits of
existence of the solid solutions, and then to proceed with the
inquuy into the variation of hardness with constitution. It
58 Greenwood : The Constitution of the Copper
was, however, only in the later stages of the work that this was
noticed. There is an advantage in the present order. Whereas
from microstructures, one can only get an idea of the gross homo-
geneity or heterogeneity of the alloy, hardness tests, being con-
cerned more with molecular conditions, may serve as a finer
guide to the internal constitution than would a microscopic-
examination. To give a typical example of this, an 8*7 per
ceiit. Al alloy as cast has a duplex structure, d -^ 0. By
reheating to 700° C. for 15 minutes, it becomes to all appearance^
structurally homogeneous. By a further annealing at 600° C,
however, the hardness gradually falls and does not reach a con-
stant value for many (10 to 20) days. This is due to the gradual
diffusion of the richer Al portions (the y3 areas in the chill cast
alloy). Hence, although microscopically this is complete after
several minutes, it may not be actually so for several days. Thus
useful information as to the rate of diffusion (and therefore
of the time necessary to reach equilibrium) in these alloys has
been obtained by means of hardness tests.
Besides these two papers, there are others which deal with
particular aspects of the hardness of Al-Cu alloys. These refer
to the change in hardness which some of the alloys (9-16 per cent.
Al) undergo when rapidly cooled, so as to retain the /S solid
solution, in place of the corresponding a + S conglomerates.
The hardening of metals by quenching so as to suppress (or
depress) a transformation, which with slow cooling would have
taken place at a moderately high temperature, has been the
subject of much discussion. But the results and theories of
different investigators are at variance. As an example, we may
take the work of Edwards * and of Andrew.f In the former
paper (p. 157) there is this statement : " Al-Cu alloys containing
about 9-16 per cent. Al are immensely harder after quenching
from about 800° C. than if allowed to cool slowly from that
temperature. ..." In the latter paper (p. 35) we have "...
the results obtained with Al-Cu and Sn-Cu alloys support the
contention that quenching an alloy of this character, and thereby
preventing the resolution of a single homogeneous phase into
two other phases, rather than effecting a hardening, may cause
* Jouriiai of the Iron and Sled Institute, 1910 (ii.).
t Internationale Zeitschrift fiir Metallographie, 1914.
Rich Aluminium-Copper Alloys 59
the alloy to become less hard than if the transformation was
allowed to take place."
It is obvious from such contradictory statements that the
facts concerning the relative hardness of the a ■\- h, and
corresponding /3 solutions, are not known with sufficient fullness
or accuracy.
The present paper deals with the variation of hardness, with
the composition, and with the heat treatment of alloys con-
taining 0-16 per cent. Al, and for the time being no theoretical
considerations of the results are offered. This reservation has
been considered necessary, owing to the uncertainty of the
effects of rapid cooling in bringing about the suppression of
the decomposition of a solid solution into two others. The author
hopes shortly to publish the results of experiments dealing more
specifically with the relationship between the y8 solution and
its decomposition products — the a -\- ^ and /3 + ^ solutions.
Materials Used and Analysis of Alloys.
T%e alloys were made from best selected copper and aluminium
of 99*5 per cent, purity. The metal was melted in a Salamander
crucible in an injector furnace ; the contents stirred with a
carbon rod, and then poured into chill moulds.
The only comment which need be made regarding the prepara-
tion of the alloys is in connection with the evolution of heat
which occurs when Al is added to molten Cu. The present
observations are in agreement with those of Curry and Wood,*
namely :
(a) When the Al is added in small quantities at a time,
the heat evolution is noticed after each addition.
(b) If a 10 per cent. Al aUoy is melted down and more Al
added, the evolution is still obtained.
Hence the phenomenon cannot be ascribed to deoxidation
of the copper (Carpenter and Edwards, loc. ciL), but is due to
either (or both) heat of solution (Curry and Wood, loc. cit.) or
lieat of formation of CU3AI.
The analyses of the alloys are given in Table II. The
percentage of Al has been found by difference.
* Journal of Physical Chemiatry, 1907, p. 46.
60
Greenwood : The Constitution of the Copper
For convenience of reference the alloys have been given
numbers which are ten times the percentage of Al they contain,
e.g. an alloy containing 9*5 per cent, is known as No. 95.
Table II. — Analytical Results.
No.
Copper
Alnmininm
No.
Copper
Alaminium
per Cent.
per Cent.
per Cent.
per Cent.
25
97-48
2-5
112
88-72
11-2
45
95-48
4-5
123
87-62
12-3
61
93-86
6-1
126
87-32
12-6
81
91-86
8-1
127 (D)
87-30
12-6
87(A)
91-25
8-7
133
86-61
13-3
04
90-51
9-4
134(F)
86-58
13-4
97(B)
90-23
9-7
140
85-92
140
100(C)
89-90
10-0
145
85-44
14-5
105
89-46
10-5
155
84-48
15-5
110
88-94
11-0
158
84-18
15-8
Preliminary Experiments.
Before commencing the actual research several points required
investigating in order to define the experimental methods at
the outset.
These preliminary experiments may be divided into two
classes :
(a) Those dealing with the influence of certain factors on the
methods of measuring hardness.
{h) A survey of the effect of heat treatment on several of the
alloys.
In many cases two different instruments have been used to
measure the hardness, namely, that of Brinell and the Shore
scleroscope.
The following is a summary of the factors which it was
thought might affect the experimental results obtained by these
methods :
(1) Afjecting Die Brinell hardness numbers :
(a) Thickness of specimen.
(&) Time of application of load.
(c) Magnitude of load.
(d) Mode of distribution of constituents.
Rich Alluminium-Copper Alloys 61
(2) Affectmg scleroscope hardness numbers :
(a) Thickness of specimen.
(b) Smoothness of surface.
(c) Distribution of constituents.
{(I) Inclination of upper and lower surfaces of specimen,
^•which should be parallel.
As there has not been sufficient time to make a thorough
examination of all these factors, it was decided to adopt the
following plan :
(1) To determine the effect of thickness on the Brinell and
scleroscope numbers.
(2) To vary the magnitude of the load in the Brinell
test.
(3) To find the effect of smoothness of surface on the sclero-
scope number.
As regards the other factors, the possible variation has been
reduced to a minimum by standardizing the methods of experi-
ment, as is explained below.
j < ' Time of Application of Load in Brinell Tests.
Thomas * has shown that in testing the hardness of mild
steel by this method, the hardness number decreases as the length
of time during which the load is applied increases. As would
be expected, the relationship is not a linear one, some 60 to 70
per cent, of the total decrease occurring when the load has been
applied for one minute and the remaining 40 to 30 per cent, only
after one hour. Since the actual difference between the Brinell
numbers after, say, one second application of load, and one hour
application, is only a matter of 10 per cent, of the actual number,
with soft steels (hardness about 120) and considerably less with
harder material, it will be recognized that no great discrepancy
can arise from this point.
In order, however, to be certain that this did not enter as a
variable into the present work, it was decided to adopt a standard
time of 30 seconds for the application of the load. This has been
carefully adhered to throughout.
* Journal of the Iron and Sled Institute, 1916 (i.), p. 258.
G2 Greenwood : The Constitution of the Copper
Mode of Distrihuiion of Constituents.
Grenet {loc. cit.) considers that, in general, segregation of the
constituents of an alloy brings about a softening. This conforms
to generally accepted views, especially with regard to steels, it
being well known that sorbite is considerably harder than the
more structurally resolved pearlite.
Andrew [loc. cit.) also shows that, in the case of Al-Cu alloys,
an annealing at 500° C. causes a marked softening, as is shown
by the following figures :
Table III.
Aluminium per Cent.
Brinell Hardness.
Furnace Cooled. : Annealed^ive Hours.
10-0
10-5
110
120
12-5
130
180
226
284
416
416
416
196
246
299
broke
But since these figures are accompanied by the statement :
'* It certainly lends no support to the view that segregation
causes a decrease in hardness . . .," it is doubtful whether
these figures are correct.
It is possible to deduce some general principles, in order to
see w^hat one would expect under ideal conditions.
Andrew {loc. cit.) says, ". . . any constituent in great
excess, in virtue of its mass, having a preponderating influence
(on the hardness) and masking to a large extent the effect of
the other constituents."
It would appear that this is the most reasonable thing to
expect, especially when there is a big difference in the hardness
of the respective constituents. The results obtained show that
this is not necessarily the case. The above statement can b€
represented graphically in the following manner.
Assuming that the alloys consist of simple mixtures of th
two components, then if the relative quantities of the coo-
Rich Aluminium-Copper Alloys
63
Istituents present have no influence upon the magnitude (per unit
mass or volume) of their respective effects, the relationship
between hardness and composition should be linear, as shown
by the dotted line ah in Fig. 2. If, on the other hand, the
influence (per unit mass or volume) is a function of the relative
quantities present, in the sense that as the quantity of A or B
increases the relative influence of A or B also increases, then
the hardness composition curve should depart from a straight
C 0 MPOS I T I 0 N
Fio. 2.
line. With A in excess the alloys would be softer than "would
be calculated from a linear equation, whilst with B in excess
they would be harder. There would be a point of inflexion in
the curve which might occur anywhere, according to the respective
influence of the two constituents and also upon the constitution —
i.e. on whether the primary constituent, say, of an eutectic or
eutectoid was the soft A or the hard B. In the case of the simple
mixture taken above, the point of inflexion would occur at about
50 per cent., as shown by the full curve o i fc.
It would be expected that alloys would more nearly conform
to the linear relationship, the finer the state of division of the
constituents.
64 Greenwood : The Constitution of the Copper
The results obtained during the present investigation tend
to show that, provided the alloy has been allowed to reach
equilibrium, the distribution of the constituents has no appreci-
able effect on the Brinell hardness number. This point is
referred to later.
As regards the influence of this factor on the scleroscope
test, in general, the above remarks also apply here. In addition
it is necessary to note that the scleroscope results are much
more likely to be erratic from this cause, because (a), the area on
which the test is made is considerably smaller than in the case
of the Brinell, and so the chance of obtaining an average value
in any single test is much less ; and (h), the time during which
the load is applied, is only a small fraction of that used in the
Brinell test, and so there is less chance of an equilibrium being
set up, as a result of which it is more likely to be influenced by
the character of the constituent first struck (especially if this
happens to be the harder one).
From this it will be understood that the scleroscope requires
handling with care, when testing alloys in which large structures
are obtained, consisting of constituents of widely differing hard-
ness. The present case of Al-Cu alloys is a particularly bad
one from this point of view. Nevertheless, by taking a large
number of tests over a wide area, it is remarkable how closely
the form of the curves for the two sets of tests agree wdth one
another even in so extreme a case.
It should be mentioned that the magnifier hammer has been
used throughout this work. This is designed so as to give a
greater rebound with soft materials than does the standard hammer.
Inclination of Two Opposite Surfaces of Specimen.
Although in the scleroscope tests considerable annoyance has
been given by this variable, there has not been time to examine
the limits of deviation from the parallel allowable in order to
get satisfactory results. From general evidence, however, it can
be said that, in the case of small specimens at least, the limits
are very narrow. It has often been noticed that a rebound 50
per cent, low could be obtained consistently, due to the surfaces
not being parallel. Since, in the test itself, there is n^^ indication
Rich Aluminium-Copper Alloys
65
(except the sound of the striking hammer) to indicate whether
the result is a trustworthy one or not, the need for extreme care
cannot be too strongly enforced when using this instrument.
This trouble becomes more marked the harder the alloy,
probably owing to the fact that in the case of softer material a
certain amount of self-adjustment takes place.
The effect would probably be less, too, the greater the mass
of the specimen. Since, in the majority of the tests about to
be described small specimens were essential, it is just possible
that this trouble has been encountered to an exaggerated extent.
Thickness of Specimen.
For these experiments four specimens were used, each being
1 in. diameter, the thicknesses being 0*2 in., 0*4 in., 0*6 in,, and
0*8 in. respectively. The specimens were ground to a level
surface and finished with emery paper. The alloy used con-
tained about 10 per cent. Al, and the tests were made on chill
cast, water-quenched, and tempered specimens. The results
are given in the following tables :
Table IV. — Alloy as Cast.
Surface Finish.
Thickness.
Brinell
(3000 Kg.).
Scleroscope.
Average.
F emery
Inches.
0-23
0-42
0-64
0-84
Mean Brinell
128
133
126
134
130
30, 30, 80, 30
29, 30, 30, 29, 29
27, 27, 27-5
26, 27, 27, 26-5
30 .
29-6
27
26-6
Table V. — Specimens Water-Quenched, 900° C.
Surface Finish.
Thickness.
Brinell
(3000 Kg.).
Scleroscope.
Edge. Centre. Average.
F emeiy
»»
Inchea.
0-2
0-4
0-6
0-8
201
234
176
168
48, 43, 27, 28, 28, 35, 40, 43 36
42, 47, 53, 60, 61, 63, 63 58
37, 37, 41, 41, 44, 45, 46 41
40, 41, 42, 45, 46, ... | 43
1
VOL. XIX.
66 Greenwood : The Constitution of the Copper
Table Nl.—Water-Quenclied, 900° C. Tempered, 410° C.
One Hour.
Surface Finish.
Thickness.
Brinell
(3000 Kg.).
Scleroscope.
Edge. Centre.
1
Average. 1
000 emery
Inches.
0-2
0-4
0-6
0-8
175
178
168
166
42, 34, 28, 32, 37, 43, 45
43, 45, 46, 48, 49, 47, 47
35, 37, 38, 40, 42, 43, 45, 46
44, 44, 46, 44, 45, 47, 47
37
46-6
41
45
These results bring out several important points. When the
specimens are in the same physical state {e.g. when cast and
when tempered) there is no great effect on the Brinell figure
when the thickness of specimen is varied between 0*2 in. and
0*8 in. (maximum variation, + 4 per cent.).
The scleroscope tests on the 0*2-in. specimen are very erratic.
Such differences as occur in the other series are of a systematic
nature and indicate definite differences of hardness.
There is a marked increase in hardness (as shown by the
scleroscope) from outside to centre. This is probably a casting
effect aided by slight segregation. It has been noticed through-
out the work, so that in every case scleroscope hardness tests
have been taken at regular intervals from outside to centre
(approximately every 0*1 in.) and a mean value taken, and Brinell
tests have always been taken midway between the centre and
edge of the specimen.
It can be said from these results that for Brinell tests specimens
of 0*2 in. thickness can be used safely, but for the scleroscope
tests it is advisable to use thicker pieces. Wherever possible
this general rule has been followed, but in the case of duplicates
in some quenching experiments (pp. 73-79) specimens of only
0*1 in. thickness were necessary.
Effect of Surface Finish on Sclerosco'pe Tests.
Three different finishes were tried, using 0, 00, and 000 emery
respectively. Since the same four specimens were used as for
the " thickness " experiments, a further finish — F emery {i.e.
much coarser) — ^can be added for comparison. The results
obtained are tabulated below (Table VII.).
Rich Aluminium-Copper Alloys
67
This series of tests bears out the former series on the effect
of thickness, showing clearly that the results obtained with
specimens 0*2 in. thick are very erratic, whereas with a thickness
of 0*4 in. and over the result? are quite constant.
A wide variation in the roughness of surface is evidently
allowable, but all subsequent tests were made on a surface obtained
with 000 emery before polishing for micro-examination.
Table VII. — Alloy as Cast.
Effect of Surface Finish on Scleroscope Hardness.
Finish.
Thickness.
Scleroscope Hardness.
Average.
F
0
00
000
Inches.
0-2
0-4
0-6
0-8
0-2
0-4
0-6
0-8
0-2
0-4
0-6
0-8
0-2
0-4
0-6
0-8
30, 30, 30, 30 30 v
29, 30, 30, 29, 29 29-5
27, 27, 27-5 27
26, 27, 27, 26 26-5 )
25, 24, 25-5 25 .
28, 27-5, 28-5 28 1
28, 29, 29 29 f
31,31-5,31 31^
19, 20, 19, 21 20 V
28-5, 28, 28 28 |
29, 29, 29 29 f
31-5, 32, 31-5 31-6 1
15, 16, 16, 17-5, 19, 20, 22 18
26, 26, 26 26 ^
26, 27, 26-5 26-6 -
30, 29-5, 29-5 29-5 J
28
29
29
27
1
Effect ofiyaryingLoadonJBrinellJ^umher.
This is the only remaining factor which it was thought
necessary to investigate before proceeding with the actual
research.
In considering the best value for this variable, two factors
come into play. First of all, in order to compare the present
with previous work on the same alloys, and on steels especially,
it is advisable to use the standard load of 3000 kg. But, on
the other hand, this has the disadvantage that it limits the
range of application of the Brinell test, owing to the fact that
alloys containing more than 14 per cent. Al are very brittle
in the annealed state.
68 Greenwood : The Constitution of the Copper
Moreover, since the Brinell number varies with the load
applied, which particular load is to be chosen when attempting
a comparison with scleroscope hardness tests ?
Thomas {loc. cit.) has shown that in the case of mild steels
a constant number is obtained by using a modified value (P^)
for the pressure P in the equation —
This modified pressure is given by
3000 + K ^ ^ ''
where K is a constant depending "on the material, thickness
of specimen, &c. For P = 3000 kg. the correction, as seen from
the equation, is zero.
Carpenter and Edwards {loc. cit.) give two curves for a
series of Al-Cu alloys, using two loads — 1034 kg. and 3000 kg.
respectively. Their results are reproduced in Table VIIL, with
the addition of the ratio of the hardness numbers obtained for
the two loads. A glance at these ratios shows that there is
no definite relationship between the two sets of figures.
Table VIII. — {From Eighth Report Alloys Research Committee.)
Brinell Hardness * vising Two Loads.
Alnminiiim
per Cent.
1
1
Constitution.
Brinell Hardness.
H,o,.
1034 Kg. 3000 Kg.
1
HlOM
1
i 6-07
7-35
9-90
11-73
13-02
13-50
15-38
a
a
a + /3
)3
a or 3+S
a + 5
a+8
113
123
180
213
332
372
411
124
134
210
269
349
437
639
110
1-09
117
1-26
1-05
1-17
1-31
♦ The hardness figures given in this table are not comparable directly with those obtained
n the present work, as these authors used Benedick's modified value
where p is the radius of the steel ball. The hardness number thus becomes independent of
the radius. Hence the values above need to be divided by 1-367 in order to be comparable
with those contained in this paper.
Rich Ahiminium-Copper Alloys
69
In view of this uncertainty, it was decided to make a pre-
liminary examination of this effect, and ■ also in the subsequent
work to use whenever possible two different loads (1500 kg.
and 3000 kg.).
The results of these comparative tests on six alloys in the
/500 2000 2500
LOAD IN KOM
Fio. 3. — ^Variition of Biiaell Hardness Number with the "Applied Load.
chill cast state are given in Tables IX. and X., and are plotted
in Pig. 3. The tests were made on specimens 1 in. diameter by
I in. thick, and two sets of determinations ^\^ere made. Those
values indicated by a cross in Fig. 3 were obtained by making
a separate impression for each load, whilst those indicated
by a dot were obtained by replacing the ball in the same im-
pression for successively increasing loads.
70 Greenwood : The Constitution of the Copper
The loads used were 500 kg., 1000 kg., 1500 kg., 2000 kg.,
3000 kg., and 4000 kg. In each case the load was applied for
30 seconds.
Table IX. — Effect of Pressure on Brinell Number. {Chill Cast Alloys.)
Same Impression for Successive Loads.
1
Brinell Hardness.
,
Alaminium
1
per Cent.
r
500 Kg.
1500 Kg.
3000 Kg. ;
4000 Kg.
8-7
o (annealed)
2-72 84
4-34 99
1
5-79 103 !
6-64 101
9-7
o + eut.
2-50 100
405 HI
5-27 127 i
610 123
100
a 4- eut.
2-34 115
3-69 135
4-85 152
6-54 152
12-6
5 -r eut.
1-99? 159
2-96 213
3-79 256 '
4-49 239
13-3
5 + eut.
1-54 ? 281
2-46 310
3-20 364 j
3-67 365
14-3
5 + eut.
...
2-41 324
3-21 362
3-68 359
Table X.
Separate Impression for each Load.
Brinell Hardness.
Alaminium
per Cent.
500 Kg. 1000
Kg.
1500 Kg.
2000 Kg.
3000 Kg.
4000 Kg.
8-7
2-78 81 i 3-62
94
4-36 95 4-74 106
5-75 105
6-45 108
9-7
2-59 93
3-29
114
3-94 118 ' 4-39 126
516 133
5-80 137
100
2-38 111
3-15
125
3-71 134 414 142
4-85 152
6-65 145
12-6
1-94 168
2-53
196
2-93 217 3-32 226
391 240
4-49 240
13-3
1-54? 281
2-06
297
2-41 323 2-72 337
3-24 353
3-71 357
14-3
...
203
305
2-39 329 2-70 341
3-20 364
3-64 372
From these figures, and still better from the corresponding
curves, it will be seen that there is a gradual rise in the hard-
ness number as the load increases to 3000 kg., but after this it
is practically constant.
In Table XL are given the ratios of the numbers (H3000)
obtained with a load of 3000 kg. to those (H^) obtained with
other values {x) of the load.
Rich Aluminium-Copper Alloys
71
Table XI.— Values of the Ratio ^^•
Aluminium
per Cent.
H«00((
Hjoo
■"1000_
Hiooo
H»ooo.
H,,oo
■tljooo
Hjooo
Haooo.
Hjooo
Hjooo
H,o,0'
8-7
1-30
112
MO
0-99
1-00
0-97
105
9-7
1-43
1-17
113
1-05
1-00
0-97
133
100
1-37
1-22
113
1-07
1-00
1-05
152
12-6
1-43
1-23
Ml
1-06
1-00
1-00
240
13-3
...
1-26
109
105
1-00
0-97
353
It will be seen that the ratio
H,
is comparatively constant
■^-^1500
for the series of alloys, and has an average value of 1-11. The
results of a preliminary series of heat treatment experiments are
shown in Fig. 4, the ordinates being hardness numbers obtained
with a 3000 kg. load, and the abscissae hardness numbers obtained
with a 1500 kg. load. The equation for this curve is : H3ooo =
1-06 Hisoo, and most of the observed points fall within 5 per
cent, of this. It would appear that even when great care is
taken with the Brinell test, the results are only accm^ate within
+ 5 per cent, of the true number.
Although this work has not been carried far enough to admit
of any general deductions, there are several interesting points
about the hardness-load curves which might repay further
investigation. The equations for five of the curves are given
below, representing the results obtained with loads of 500 kg.
to 3000 kg. inclusive.
Aluminium
per Cent,
8-7
H =. po'ias 4- 101*55
9-7
H = po-i« + 101 '6'
10-0
H = P0"17 + 101'59
12-6
H = pO-20 + 101-69
13-3
H = PO-18 + 101-M
Where
H
= Hardness number.
P
= Load in kg.
Extrapolating from these equations, the curves in Fig. 3
have been extended to the zero-load axis (the extrapolated
portions of the curves are shown in broken line). It would be
very interesting to know the physical meaning of the constant
in the equations, for experimentally the cm-ves must all start
72 Greenwood : The Constitution of the Copper
from zero. It seems probable, therefore, that this constant
might represent the hardening effect of the cold work which
necessarily accompanies the test.
T^ 160
/
/
/
•
/'
1
/
/
•/
/,
/
/
/
/
60 100
Sni NELL
140 180 220 260
HARDNESS (1500 KGM.)
Fig. 4, — Relationship between Brinell Numbers obtained with 1500
Kg. to those with 3000 Kg. Load.
Summary of the Preliviinary Experiments on the Brinell
and Scleroscope Tests.
1. It has been decided to adopt a standard time for the
application of the Brinell load, namely, 30 seconds.
2. With coarse structures consisting of two constituents
of widely different hardness, scleroscope tests must be made
with great care, and the average of a large number of tests taken.
The effect on the Brinell test is naturally much less.
Rich Aluminium-Copper Alloys 73
3. For Brinell tests the specimens need not be thicker than
0*2 in., but with the scleroscope the results are erratic with this
thickness, but are quite consistent with specimens of 0*4 in.
thick and upwards.
4. A wide variation in smoothness of surface is allowable
for the scleroscope tests. However; a surface finish with 000
emery has been used for all hardness tests.
5. The Brinell hardness number increases with the load, but
becomes comparatively constant with a load of 3000 kg. and
upwards. The ratios of the numbers obtained with a load of
3000 kg. to those obtained with other values of the load have
been determined within the limits of accuracy of the method,
so that a hardness number obtained with 1500 kg. load can be
converted for comparison with a 3000 kg. number.
6. Extrapolation to the zero-load axis by means of equations
connecting the hardness with the pressm-e shows that there
is a fraction of the " hardness number " which is independent
of the pressure, but varies with the material. This may in some
manner be connected with the " cold-work hardening power."
The Effect of Quenching Temperature on the Hardness of Alloys
containing 9 to 16 yer Gent. Aluminium.
It is well known that in certain classes of steel raising the
quenching temperatm-e above that necessary to obtain all the
elements in solid solution results in a more perfect retention
of the " hot stable " state.
The following experiments were carried out to determine
whether this was the case with Al-Cu alloys, and also to see
how the hardness changed when various structural changes
were brought about by heat treatment. Andrew {loc. cit.) draws
attention to the fact that for an alloy containing 12-5 per cent.
Al " no difference in the hardness was detected, the values
being the ^me for quenching at all temperatures between 570° C.
and 1100° C." This statement has been confirmed by the present
work, but since the alloys in the neighbom-hood of the eutectoid
point (12 per cent. Al) are the easiest to retain in the /3 condition,
it was thought advisable to repeat the experiments with alloys
of varying composition.
74 Greenwood : The Constitution of the Copper
Accordingly alloys containing 8-7 per cent., 9*7 per cent., 10-0
per cent., 12-6 per cent., and 13-3 per cent. Al were quenched
from successively increasing temperatures, a separate piece
being used for each experiment.
The test-pieces were all 1 in. diameter and 0*4 in. thick. In
the cases of alloys 10-0 %, 12-6 %, and 13-3 %, duplicate pieces
0*1 in. thick were quenched along with the larger specimens. In
such cases the two specimens were placed side by side in a tube
furnace, and after the desired heating they were rapidly removed
(separately) by means of an attached loop of wire and quenched.
The alloys were originally in the chill cast state, and were
" soaked " for 15 minutes at the maximum temperature (registered
by a thermocouple placed alongside the specimens), except in the
case where Tmax. = 1000° C, when only 5 minutes was allowed,
owing to the rapid giowth of the grains at this temperature.
After the quenching, Brinell and scleroscope determinations
were made and the microstructm'e examined.
The results are given in Tables XII. to XVI., and are plotted
in Fig. 5 (p. 77). Since in the cases where duplicate specimens of
Table XII.
Alloy, 8-7 per Cent. Aluminium. Effect of Quenching Temperature.
Pieces 1 in. X 0-4 in. Temperature of Water, 11" to 20° C.
* T. IB tempered. W.Q. = water qoendied.
Rich Aluminium-Copper Alloys
75
Table XIII.
Alloy, 9-7 per Cent. Alummium.
Weight
of Treatment.
Piece.
Scleroscope. Brinell.
Constitution.
Min.
Max.
Av.. 'kT
3000
Kg.
§ T. 1 hour
S i » 22 hours
o W.Q. 690° C.
t»^ i „ 650 „
'2 § ! „ 700 „
a^ ,. 760 „
•§§ : ., 810 „
2" „ 850 „
£■- ' ,, 880 „
■a to
■2 „ 950 „
o
a
o ,, 1000 „
34
27
25
25
34
36
42
42
44
36
30
35
32
30
32
36
39
46
47
46
42
39
35 134
28-5 1 135
27-5 , 118
28-5 ' 122
35 134
37 136
44 160
44 166
45 159
39 i 159
34 153
145
,147
~136 ;
126 X
138 |T
Tl55
172
177
'178 ~
168
162
o + eutectoid.
0 + /3.
a + iS (increasing).
a + $, chiefly /3.
a + 3, ground-mass is a
fine mixture of a + /3.
chiefly o.
Fine mixture of a + )3,
chiefly a.
Table XIV.
Alloy, 10-0 per Cent. Aluminium.
Weight
Scleroscope.
Brinell.
of
Treatment.
Piece.
Min.
Max.
42
Avg.
1600
Kg.
3000
Kg.
1
T, 1 hour
31
37
171
178
1
„ 22 hours
33
41
36
166
178
o 4- eutectoid.
W.Q. 590° C.
35
41
38
141
147
o + ;8.
,, 650 „
37
41
40
148
160
»
» 700 „
39
50
45
176
184
»
o
,, 750 „
56
59
57
192
212
»
^
» 810 „
70
81
74-5
264
270
Very complex. 3 on
edge, a + P inside.
•^
„ 850 „
80
82
80-5
250
279
Chiefly /3, decompos-
>»
ing to a + jS. No
massive a.
B
,, 880 „
65
86
74
271 1
Almost pure /3, but in
g
parts fine mixture
S.
a + j8.
<)
„ 950 „
70
70
70
262
264 !
j
a + fi, fine mixture $
chiefly.
.. 1000 „
248
240
o + j8, fine mixture, o
chiefly.
'1
7G Greenwood : The Constitution of the Copper
Table XV.
Alloy^ 12*6 per Cent. Aluminium,
Quench-
Tem-
Time
Soaked.
Weight
Brinell
ing Tem-
perature
of Speci-
(1600
scope.
Constitution.
perature.
ofWater.
men.
Kg.).
Deg. C.
Deg. C.
Mine.
Grms.
600
8
16
10-3
...
...
...
...
34-86
260
71
3-1-5.
660
9
jj
10-5
...
...
34-3
191
67-5
e + S-
700
i'6
jj
10-9
• ••
66
36-0 ,
186
61-5
B.
750
9
jj
1015 :
• ■•
55
...
...
35-76 i
186
47
$■
810
10
jj
11-2 '
...
50
...
30-2
182
46-6
fi-
860
9-5
„
11-5
63
...
37-3
187
60
)3.
900
8
"
121 ;
38-25 1
183
57
52-5
/3. Marked surface deformation.
960
...
9
"
7-6 ,
36-7 !
168
61
49-5
j8. Minute pimples on surface.
1000
9
,,
90
...
...
fi. Marked surface deformation
...
35-6
182
49-6
and few pimply patches.
Table XVI.
Alloy, 13-3 per Cent. Aluminium.
Quench-
Tem-
Time
Weight
Brinell
Sclero-
ing Tem-
perature
Soaked.
of Speci-
(1600
perature.
of Water.
men.
Kg-).
Deg. C:
Deg. C.
Mins.
Grms.
600
8
15
7-7
89
...
...
37-4
306
76
660
9
"
9-5
...
Very
variable i
...
...
...
34-4
286
79-6 '
700
9
„
8-7
76
...
36-6
272
74
750
8
"
7-3
Very
variable
...
35-5
260
71
810
8
„
8-5
...
73
...
...
36-4
303
77
860
9
„
7-1
...
63
...
...
35-3
298
74-5
900
7
7-6
3
...
...
37-3
262
69
960
7
„
10-2
...
76
...
...
...
36-0
295
76
Constitution.
B + S-
e + 8.
j3 + 5.
Pure j8 round edges.
Very variable.
/3 in parts. ;8 H- 7 in others.
Rich Aluminium-Copper Alloys
11
different size were employed, the hardness -quenching tempera-
ture cm:ves run practically parallel with, though slightly above
SS3Nad\fH njNIiJB
/
I
/
/
J-
\
/
\
© ^
Y
\
9S3N0 d V H 3d03 SOUTHS
. D
r-*»
-ti eS
S ^
^ an
O .2 I
(scleroscope tests) or below (Brinell tests) those corresponding
with the larger specimens. They have not been included in
Fig. 5 in order to avoid confusion.
78 Greenwood : The Constitution of the Copper
Considering these curves now in detail, it is seen that the
first effect of raising the quenching temperature of alloy 87
is to cause a softening, due, as is seen from the microstructure,
to the disappearance of the /S solution of the chill casting, until
at 700° C. a minimum hardness is reached, and all the y9 has
become a with its typical broad " twin " markings. It will be
shown later that such an alloy has by no means reached equili-
brium. On further raising the quenching temperature the
a 4- /3 area of the phase diagram is again entered and the hard-
ness gradually increases with the quantity of yS. This curve
is chiefly of interest as showing how delicately hardness deter-
minations follow phase changes.
The curves for alloys 9-7 % and 10 -0 % show an increase in
hardness with quenching temperature until a temperature of 850°
to 900° C. is reached. In both of these cases quenching at j
higher temperatures gives rise to a slight softening, as shown
by both the scleroscope and Brinell tests. It is however not
due to a better retention of the hot stable state, but to a greater
decomposition of the ^ solution. Alloy 10-0 % becomes pure ^
between 850° and 900° C, but the retention of this state com-
pletely by quenching has been found to be impossible even with
a specimen weighing about 5 grms. The effect of increasing the
temperature is apparently to cause a slower cooling, with a
consequent greater decomposition of the /3 solution. The
microstructure of a specimen quenched from 900° C. and of
one quenched from 1000° C. are shown in Nos. 5 and 6, Plate I.
It will be seen in the latter case the decomposition has gone
very far.
Alloy 12-6 % is on the other side of the eutectoid point, and
the /3 to /3+S transformation is only about 100° C. above the
eutectoid transformation. In this case raising the quenching
temperature causes a marked softening until the alloy is re-
tained as pure yS, and after this there is no definite change in
the hardness. This alloy is very readily obtained as pure /3,
even in large specimens.
The experiments carried out on alloy 13*3 % are only interest-
ing as showing the rapid change in the velocity of decomposition
of the ^ solution, with comparatively small changes of com-
position. It was found to be impossible to quench eflSciently
Auoy lu/o .-i
No. 1.— 40 grm. Specimen W.Q. 600OC
Structure a+fi. Brinell hardness, 141 ;
Scleroscope hardness, 38. Magnifica-
tion 60 diameters.
No. 3. — 40 grm. Specimen W.Q. bSO'^C.
Structure /3 decomposing. Brinell
hardness, 2.50 ; .Scleroscope hardness,
80"5. Magnification 60 diameters.
^m^^-'
No. 2.— 40 grm. Specimen W.Q. 7600C.
Structure a+$. Brinell hardness, 192 ;
Scleroscope hardness, 57. Magnifica-
tion 60 diameters.
No. 4.-5 grm. Specimen W.Q. 8.50°C.
Structure almost pure fi. Brinell
hardness, 254. Magnification 60 dia-
meters.
1.
M0%:^-.jM^
No. 6.— 40 grm. Specimen W.Q. 1000°C.
Structure fine mixture of o+j8.
Brinell hardness, 248 ; Magnification
500 diameters.
Keduced bv one-hlth.
No. 7.— Alloyly-3 ;^A1. w .(j. 810'-C. Extreme
edge. Structure y3. Magnification
150 diameters.
No. 9.— Alloy y T-p --'• Annealed at 6(X)=C.
for 13 days. Structure a. Brinell hard-
ness, 76. Magnification 60 diameters.
K^sm^"^
No. 11.— Alloy 11-2;/ Al. Very slowly
cooled. Structure a+eutectoid. Brinell
hardness, 205 ; Scleroscope hardness, 44.
Magnification 60 diameters.
y^K
\
No. 8. — San.' _ : .en as No. 7. Interior
unetched. Brinell hardness, 303;
Scleroscope hardness, 77. Magnifica-
tion 150 diameters.
No. 10.— Alloy 10/^ Al. Annealed iij
'600°C. for 13 days. Structure o+eutec
toid. Magnification 60 diameters.
3^i -.:J^^^ >:"^^::*^. ^-V
*•&-
No. 12.— Alloy 12-3% Al. Very slo\v .
cooled. Structure 8+eutectoid. Brinell
hardness, 254 ; Scleroscope hardness
58. Magnification 60 diameters.
1
Rich Aluminium-Copper Alloys 79
10-grm. specimens of this alloy. Up to a quenching temperature of
'750° C. the alloy is found to soften. Above this temperature {i.e.
at 800° C.) the /8 area has been reached, for the quenched speci-
men has an annular band of pure ^ several mm. wide, as shown
in No. 7, Plate II. In the interior of the specimen decomposi-
tion has taken place, as indicated by the hardness having in-
creased to its original value, and also by the fact that the usual
etching reagent (FeCla + HCl) attacked it deeply immediately
when applied, thus suggesting that the alloy was a finely divided
mixture. The peculiar relief structure shown in No. 8, Plate
11. , is typical of the unetched alloy when quenched above
750° C. Eaising the quenching temperature gives similar results,
the suppression of the transformation being very variable through-
out each specimen, with consequent variation in the hardness.
This series of experiments has shown, therefore, that the /3
solution varies enormously in its transformation velocity, accord-
ing to its composition, in the sense that as the latter departs
from that of the eutectoid point the reactions ^ -> a -{- ^ and 13 ->
/3 4- S increase enormously in velocity. Another point which
has been brought out is that in the case of those alloys with
high transformation velocities (below 10 '5 per cent. Al and
above 13 per cent. Al) an increase in the initial temperature
tends to reduce the chance of retaining the pure yS solution,
possibly by reducing the rate of cooling.
Time required to Attain Equilihrium in these Alloys.
During these latter experiments the remarkable sluggishness of
the alloys (as regards equilibrium between the various soUd
solutions) was noticed, and in order to obtain an idea of the
length of time required for the attainment of equilibrium, a
series of prolonged heating experiments was carried out.
These were made on alloys 8-7 %, 9-7 %, 10 '0 %, 12-6 %, and
13-3 %, starting from the chill cast state. The specimens were
kept at a temperature of about 600° C. and periodically they were
removed from the furnace and quenched. A Brinell determination
was then made and the alloys afterwards replaced in the furnace.
The results are shown in Table XVII. and are plotted in Fig. 6.
80 Greenwood : The Constitution of the Copper
In connection with alloys 87 % and 97 % it was noticed
that even when they were structurally simple, i.e. when according
to the microstructure they consisted of the a solution, further
annealing reduced the hardness. As has been said, the alloys
as cast were duplex, and the effect of the annealing is to allow
diffusion to take place between the a and yS solutions, the former
being unsaturated and the latter supersaturated with respect
to the stable state. Now when diffusion has taken place to
Table XVII. — Time required for Specimens to attain Equilibrium
at a Temperature in the Neighbourhood of 600° C.
t
BrineU (1500 Kg.).
Length of Time
at 600° to
1
650° a
8-7 per Cent.
9-7 per Cent.
100 per Cent. 12-6 per Cent.
13-3 per Cent.
1
Aluminium.
Aluminium.
Aluminium, i Aluminium.
1
Aluminium.
Chill cast
96
118
134 217
323
15 mins.
89
118
141 1 260
306
2 days
81
...
...
...
' 4 .
81
99
116
202
264
7 ,
77
...
...
9 ,
78
107
...
...
10 .
...
...
...
11 ,
...
...
187
252
12 ,
...
...
...
...
13 .
72
...
...
...
14 .
...
101
...
...
17 .
67
...
...
...
...
, 20 ,
66
...
...
...
...
i 26 ,
68
...
...
such an extent that the previous yS areas have become super
saturated a areas (as they must in their passage towards the
stable state), they will no longer be distinguishable as a separate
constituent on etching. But since the alloy is harder than it
would be if it consisted of a mixture of two a solutions of com
positions corresponding to the unsaturated and supersaturatec
portions respectively, it seems to point to the conclusion that
although the ^ solution is not evident as a separate constituent,
there are still some yS molecular aggregates present.
An examination of the curves in Fig. 6 shows that the
complete transformation of the yS molecules takes at least
twenty days at a temperature of 600° C,
Rich Aluminium-Copper Alloys 81
General Types of Hardness-Composition Curves.
Before proceeding with an account of the further experimental
work on the Al-Cu alloys, it will be advisable to consider the pos-
sibilities which might arise in the hardness curves of binary alloys.
From the work of Km^nakow * and his collaborators, together
with that of Guertler, it is possible to draw up certain simple
320
t
"§ 28d
1
%
•
,.
\3 3%Ai
^2^0
^ 2*0
>*
i^ 200
%
Qc /60
•>4
.
'""--•
tie%A[
,,_
* - -•
\00%Al
40
.
" — •-ZZ.
" ••
ST/oAi
-••■...-
-•8-7%
Al
O 4 8 17 16 20 - 24 2c
TIME IN uTYS
Yv3" 6. — Time required for Chill Cast Alloys to reach Equilibrwaa
at 600° C.
and definite rules governing the types of hardness composition
curves of binary systems. So far these rules are purely empirical ;
they are as follows :
(1) When two constituents, whether pm-e metals or solid
solutions, form an eutectic (or eutectoid) structure, the hardness
is a linear function of the composition, within the range in which
the duplex struct m-e is formed.
(2) When a compound is formed in a series of alloys, and does
not enter into solution with its components, the curve consists
of two linear branches connecting the hardness of the compound
♦ Zeitachrifl l&r anorganischt Ghemie, 54 (149); 60 (2); 64 (149).
VOL. XIX. G
82 Greenwood : The Constitution of the Copper
with that of its two constituents. This system resolves itself
into two of type (1).
(3) ^Vhen two components form an unbroken series of solid
solutions {i.e. are isomorphous), the hardness of each is increased
by addition of the other, and therefore the hardness curve rises
to a maximum at an intermediate composition.
^li B/n
C a MPO S I T/ OH
Fig. 7.
(4) If a compound is formed which is isomorphous with both
components the hardness cm've presents a minimum at the com-
position of the compound, rising to a maximum on either side,
and falling to the hardness values of the respective components.
The hardness of the compound may be, and often is, greater than
that ot either component, although occurring at a minimum j
(Fig. 7).
From these general rules it is possible to construct hardness-
composition curves for more complicated cases, but since thesel
Rich Aluminmm-Copper Alloys
83
are only combinations of the above, it is not necessary to consider
them in detail.
Before leaving this brief sm'vey, attention must once more
be called to the possibility of cm-vatm:e occurring in those branches
corresponding with eutectic structures (p. 63). For in conjunction
with curvatme of the " solid solution lines," it is quite possible
that the boundary between two phase areas should be indistin-
guishable on the hardness -composition curve.
The Hardness of the a Solid Solutions.
With the exception of alloys 8-7 % and 9*7 %, pieces 0-5 in.
diameter and 0-5 in. thick were used for these tests. Below 8 per
cent. Al the structm-e was not examined, as the work of Carpenter
and Edwards, and of Cm-ry, has shown that under no condition
can these have a duplex structure. With higher percentages,
however, the chill cast alloys are duplex, and so it was necessary
to adopt the plan of continuous annealing at 600° C. in the same
manner as was described in a previous paragraph.
Ultimately the series of values given in Table XVIII. was
obtained for the Brinell and scleroscope hardness.
' Table XVIII. — Hardness of the a Solutions.
Aluminium jper
Cent.
nil
1-5
2-6
4-6
6-1
8-1
8-7
9-7
Brinell (1500 Kg.).
Scleroscope.
5-85 60
5-80 61
9
5-70 64
10-6
6-65 57
la
6-39 61
13-6
6-20 65
15
5-16 67
19-5
4-86 76
...
'I These Brinell hardness values have been plotted against com-
"P position in Fig. 8 (the value for the 9-7 per cent, alloy would
have fallen nearer to the curve had it been annealed for the
^' isame length of time as the alloj^s 8-1 % and 8*7 %). It is seen that
*|jthe hardness of the a solutions is a linear function of the composi-
84 Greenwood : The Constitution of the Copper
tion. This is important in view of the fact that Carpenter and
Edwards {}oc. cit, p. 268) considered that the upper limit of the
a solution range was the compound CU4AI containing 9-6 per cent.
Al. The evidence on which this was based was twofold. First
it was found that an alloy containing 9-6 per cent. Al by prolonged
annealing and slow cooling could be obtained as an homogeneous
solid solution. Secondly, by electrolysis of an alloy containing
10-7 per cent. Al, a residue was obtained which on analysis gave
9-6 per cent . Al. Neither of these tests is a criterion of the presence
70
60
%
^
' '
50
-
i»ii^
-^
""%
'
0 / 2 3 4 5 6 7 8 9/0
f Fia. 8. — Hardness of a Solutions.
of a compound, for it might be a coincidence that the limiting
solubility of the solid solution should occur at a composition
corresponding with that of a compound. Curry {]a}C. cit.) do^
not consider that there is any evidence of the existence of a
compound Cu^Al. He places the upper limit of the a solution
at 9-0 per cent. Al, and states that an alloy containing 9-5 per cent,
annealed at any temperature is duplex.
The foregoing results, however, show that the upper limit of
the solution is certainly not far from 9-7 per cent. Al, since an
alloy of this composition was actually obtained as the simple a
solution (microgiaph No. 9, Plate II.), though great care had
to be taken not to exceed 600° C. in the annealing operation.
Rich Aluminium-Copper Alloys 85
From the work of Km-nakow, of wbicli a summar}- lias been
given on p. 81, it follows (rule 4) that if CU4AI forms the limit
of the a series of solid solutions, then the hardness-composition
curve should rise to a maximum between 4 and 5 per cent. Al,
and then fall to a minimum at 9-6 per cent. Since there is no
departm-e from a linear relationship, however, it can be said that
the compound in question, although it may coincide with the
composition of the upper limit of the a solutions, does not exist
in this series.
The Hardness of the /3 Solutions.
Owing to the relatively small amount of work which has been
published on the physical constants of solid solutions which are
unstable at ordinary temperatm-es, it is difficult, if not impossible,
to predict the hardness cm've of such solutions from the equili-
brium diagram. This uncertainty is brought about by the fact
that, in order to obtain such solutions (under conditions which
give strictly comparable results), it is necessary to rapidly cool
the specimens from a temperature at which they exist in the hot
stable state, so as to preserve this in the cold, or to make the tests
at an elevated temperature (which in the present instance would
need to be above 800° C. in order to get a representative series,
owing to the narrowing of the limits of the yg solution at lower
temperatures). As regards the latter method, the ekperimental
difficulties have not yet been overcome sufficiently to make an
accurate comparison. The former method, however, whilst
opening up a large field for experiment, is limited from a theoretical
point of view, owing to the unknown effect of the quenching
operation on the hardness.
In quenched specimens it is quite possible that the hardness
is made up of two components :
(a) The actual hardness of the solid solution (when in state
of perfect equilibrium), i.e. the true hardness.
(6) A more or less complex factor due to the quenching.
It is on the nature of this complex factor that most, if not
all, of the speculation and controversy on the effect of
" suppression " of transformations on the hardness of alloys
has centred.
86 Greenwood : The Constitution of the Copper
Broadly, it is recognized that the effects of suppressing a
transformation by means of rapid cooling are as follows :
(1) A complex system of stresses is set up during the cooling,
due to unequal contraction of different parts of the specimen.
These will affect the still hot interior, and are most likely to b(
in the nature of compressive stresses on the centre. If the
transformation is completely suppressed throughout the piece,
these stresses will no longer exist when the specimen is cooled
throughout, though there may still be effects. If, however,
the transformation partially takes place — say near the centre
of the piece — this will in general be accompanied by a volume
change, and the piece will be in a state of strain in the cold.
(2) The alloy is retained in a form which (generally) occupies
a different volume from that of the stable state. Hence it is
said that stresses arise due to the tendency to revert to the stable
state and thereby occupy a different volume.
Besides these two generally accepted effects, Edwards {loc.
cit.) considers that there is another due to the " suppression "
of the heat of transformation, but this is not necessary. The
quantity of this heat which remains latent in the quenched
state depends upon the specific heats in the cold stable and
hot stable states respectively.
Edwards says : " That the act of quenching these alloys
(steels) does in reality resolve itself into some form of energy
is proved by the follo^ving reasoning :
" With slow rate of cooling the y solid solution decomposes
into a iron and carbide of iron. This change ... is accompanied
by the evolution of a considerable amount of heat. With very
quick cooling . . . the evolution of heat which would normally
occur remains in the latent state in the quenched specimen.
. . . The thermal change at 710° C. . . . can only be prevented
by the absorption of at least its equivalent amount of energy
in one form or another, and since rapid quenching suppresses
the Ar^ (carbide change) the operation must constitute a
force."
It can readily be shown, however, that this argument camiot
be accepted without a knowledge of the specific heats in the two
different states.
The latent heat of transformation from state B to state A is
Rich Aluminium-Copper Alloys 87
connected with the specific heats in these respective states by
the relationship :
g^ = Kb - Ka
where q = latent heat of the transformation from B to A.
T = transformation temperature.
K^ and Kg = specific heats in state A and B respectively.
Applying this to the case under consideration, and letting :
A = cold stable state,
B = hot stable state,
lif^ = heat of transformation at the normal transition
temperature,
\_^ = heat of transformation at the suppressed transi-
tion temperature t—x ;
then we have —
In words, for every ° C. lowering of the transformation from
its normal temperature, the corresponding heat effect is decreased
by the difference between the specific heat in the hot and cold
stable states respectively. In the limit when x =
Kb - K^
we have \-hi_^ = ht, and therefore lii^j. = 0. That is
to say, when the temperature of transformation has been de-
pressed by an amount equal to the ratio of the normal heat of
transformation to the difference between the specific heats in
the two states, then the heat evolution at this temperature will
.be zero. Hence it is seen to be unnecessary that the heat of
transformation should remain latent in the rapidly cooled alloy,
a part or the whole of it being given up as sensible heat during
cooling, if the specific heat in the B state is greater than that
in the A state.
It can safely be said that, in the majority of cases, the chief
stresses set up by rapid cooling will be compressive. This follows
from the fact that most metals and alloys have a positive co-
efficient of heat expansion, and hence the cooling must cause a
contraction. Thus pressure is brought to bear on the alloy
88 Greenwood : The Constitution of the Copper
unequally in dilfcrent directions due to variations in cooling
velocity at the surface (except in the case of spherical pieces),
and so deformation is possible. Hence although ultimately
the interior portions will contract equally as much as the exterior
portions (provided that both are retained in the same physico-
chemical state), they may have undergone profound internal
rearrangement in order to bring about a more stable distribution
of stresses whilst the latter were being applied. This disturb-
ance of the crystalline arrangement is generally looked upon as
the cause of the increased hardness of those alloys which are
hardened by rapid cooling, e.g. carbon steels and certain Al-Cu
alloys. Thus Edwards {loc. cit), and Edwards and Carpenter,*
consider that this pressure gives rise to twinning of the metallic
crystals, an operation which is considered as giving rise to
amorphous^metallic phase at the twinning planes.
With regard to the second effect of quenching (p. 86), namely,
the retention in a state having a different volume from the stable
state, this can only act in one way. 'j7hat is to say, the greater
the specific volume the lower the hardness value. This folloAvs
from the fact that the greater the distance between the molecules
or molecular aggregates, the smaller the mutual attraction of
the masses, the forces being inversely proportional to the square
of the distances apart. It is obvious, of course, that many
other factors might mask this effect, e.g. the mutual attraction
between two yS molecular aggregates might be different from that
between two a molecular aggregates. Since the tendency to
revert to the stable state is ot ordinary temperatures balanced
by opposing forces, such as viscosity (in the case of steels and
Al-Cu alloys at least), there seems little reason to suspect any
increased molecular attraction (or hardness) due to this state.
This remark refers to a completely suppressed transformation.
If, however, the latter is only partially suppressed, but in such
a way that the products are still so minutely distributed as to
form a solution, it is quite possible that the molecular forces
existing between the several different types of molecule would
be quite different from those of either the hot or cold stable |
states. This is what McCance calls " interstrain," and its
effect is obviously to cause an increase in hardness, for it brings
* Journal o/ Ike Iron and .Steel Inslilute, 1914 (n.>. p. 243.
Rich Aluminium-Copper Alloys 89
about a state of affairs similar to that contained in rule (3),
p. 82.
This summary of the possible effects of quenching is merely
I given in order to bring forward the great complexity of the con-
siderations involved. Unfortunately there seems, as yet, little
hope of being able to separate the several causes and effects.
In the present work the hardness of the /3 Al-Cu alloys has
been determined, using quenched specimens. As has already
been shown, the hardness may be composed of two factors, and
according to the relative magnitude^ of the two, it may or may
not be possible to compare the experimental with the theoretical
values (qualitatively). That is to say, if the " complex factor "
is small compared with the true hardness, then the actual hard-
ness may be taken as a measure of the latter.
The specimens used for these experiments were 0*5 in. diameter
X 0-5 in. thick. It having been shown (pp. 73-79) that quenching
from any temperature, such that the particular alloy existed
as the /3 solid solution, gave specimens of the same hardness,
provided that the same physico-chemical condition was re-
tained, the actual quenching temperatures of most of these
specimens were not recorded. The far more decisive criterion
of examining the microstructures was used to check the effi-
ciency of quenching. In no case was a hardness determination
made unless the structure was that typical of the /3 solution.
It was soon recognized that the ease with which the various
alloys (10 to 15 per cent.) could be retained as the yS solid solution
by quenching, varied enormously with the composition. Thus,
although it was possible without any particular care to obtain
11 to 13 per cent. jS solution with a 40-grm. specimen, it was
exceedingly difficult to quench efficiently 10-grm. specimens
containing about 10*5 per cent, and over 13-5 per cent. Al.
Hence in these cases the size of specimen had to be reduced
(0*5 in. diameter x 0*2 in. thick) in order to obtain satisfactory
structures. Even then, care had to be taken not to heat the
specimen higher than was necessary completely to transform it
into )8, and to increase the cooling rate by quenching in brine
at - 15° C.
Only Brinell tests are given for these experiments, as the
scleroscope readings were very unsatisfactory. The results
90 Greenwood : The Constitution oj the Copper
are given in Table XIX. and are plotted in Fig. 9. Typical
roicrostructures of the specimens after quenching are shown
in Nos. 15-18, Plate III.
Table XIX. — Brinell Hardness of /3 Series Solid Solution.
Aluminium
per Cent.
Brinell Hardness '
(1500 Kg.).
Remarks.
1
Size of Specimen.
10-5
2-56 286 i
0-6 in. X 0-5 in.
11-0
2-84 232
0-5 „ X 0-5 „
11-7
2-98 210
• 0-5 „ X 0-5 „
121
3-30 171 i
0-5 „ X 0-5 „
12-3
3-44 157 1
0-5 „ X 0-5 „
12-6
3-26 175 1
0-5 „ X 0-5 „
13-3
3-02 204
0-5 „ X 0-2 „
140
2-89 224 '
1
0-5 „ X 0-2 „
300
2S0
200
ISO
100
\
1
\
/
V
/
11
13
IS
Fio. 0. — Hardness of jS Solutions retained by Quenching.
The hardness curve is of peculiar interest, as it is of the type
shown by a series of solid solutions containing a compound,
Fig. 7. It is true that this type of curve would be expected
if the hardness tests were made at a temperatm-e at which the
Rich Aluminium-Copper Alloys 91
solution is stable. But that this should hold for the quenched
solution is rather remarkable, especially in view of the previous
ideas on the effect of quenching on these and other alloys.
The alloy containing 10-5 per cent. Al is the lowest in the
series in which it has been possible to retain the pure /3 solution.
With the 10-0 per cent. Al alloy it was impossible to suppress
completely the transformation, even by taking the precautions
mentioned above. Examination with a high-power objective
always showed that a small quantity of a had separated along
cleavage planes in the yS solution.
The hardness falls sharply down to a minimum in the neigh-
bourhood of 12-3 per cent., and with higher percentages the
curve again rises, though not so steeply.
Unfortunately it has not been possible (so far) to obtain the
pm'e yS in specimens containing more than 14 per cent. Al, and
even with this percentage it was almost as difficult as with the
10 per cent, alloj.
It has been pointed out that Edwards {loc. cit.) considers that
the quenching of the alloys brings about marked twinning of the
yS solution. That actual deformation does take place has been
noticed throughout these quenching experiments, for whenever a
smooth surface existed on the specimen the retention of the ^
was always accompanied by well-defined markings raised above
the general level of the surface. From their general characteristics
these markings probably correspond with those developed by
etching the polished surface.
The only noteworthy feature of the series of microstructures
is that between 10 to 12 per cent. Al the markings are in general
not so broad or well defined as those in specimens containing
more than 12 per cent.
Nothing further will be said at present with regard to the
hardness of the /3 solution, since experiments are now in progress
which it is hoped will throw light on the nature of this, when
retained by quenching.
The a -f S Conglomerates.
This series of alloys exists between the extreme limits of 9-7
to 16-2 per cent. Al at normal temperatm-es. They result from
the breaking down of the yS solution at about 500" C, and in
92 Greenwood : The Constitution of the Copper
general consist of an excess of (primary) a or 8, together with
a greater or smaller quantity of the eutectoid. Since there is a
ver}^ marked difference between the hardness of the two consti-
tuents, it would be expected that the hardness -composition curve
would in this case depart from a straight line in accordance
with the reasoning on p. 63.
Since as the Al content increases from 9-7 per cent, to 12 per
cent, the quantity of eutectoid gradually increases at the expense
of the primary a, until at about 12 per cent, the whole alloy
consists of the eutectoid, and afterwards the eutectoid is gradually
replaced by primary B, no sharp deviations of the curve are to be
expected. [Andrew {loc. cit.) found that the hardness was con-
stant for slowly cooled alloys above eutectoid composition. This
requires confii'mation.]
The specimens used were 0-5 in. diameter X 0-5 in. thick.
They were heated up to between 900° to 1000° C, kept there for
an hour and cooled to 500° C. in two days. This treatment was
given in order to allow the alloys to attain a reasonable state
of equilibrium.
The smfaces were then ground and Brinell and scleroscope
tests made.
The results are shown in Table XX. and plotted in Pig. 10.
(Full line, Brinell curve, and broken line, scleroscope curve.)
Table XX. — Hardness of a -\- S Conglomerates.
Hardness.
No.
Aluminium
per Cent.
Scleroscope.
21
Brinell (1500 Kg.).
B
9-7
4-86
76
C
100
26-5
3-90
120
1U5
10-6
30
3-76
130
110
11-0
36
3-21
180
112
11-2
44
3-01 205
123
12-3
68
2-72 264
126
12-6
62-5
2-68
280
133 •
13-3
...
2-51
298
F
13-4
72
2-47
308
145
14-6
2-34
344
155
15-5
...
2-28
362
It will be noticed that the scleroscope curve is a straight line,
Great difficulty was met in getting reliable figures with these
small specimens, particular care being necessary that the two
Rich Aluminium-Copper Alloys
93
plane sides of the specimen were parallel. Even then it was
found impossible to get reliable figures when the Al content
was greater than 14 per cent.
The Brinell curve is more interesting in that it exhibits the
curvature mentioned on p. 63, though in a different degree.
380
/
■^^^
340
y^
/
y/
300
/
y
/*
260
220
/
/'
/
*
/
/
180
i
, /
/
/
/
/ ./
60
I.
/*
80 Vj
3
70 <
9 10 II l\ 13 14 15 16
FiQ. 10.— Hardness of Alloys 9 to 16 per Cent. Al, a + 5 Area.
Full line — BrineU hardness.
Broken line — Scleroscope hardness.
It is obvious from the shape of the curve that the " extra "
influence of the 8 constituent comes into play almost with its
appearance in the alloys. Hence we find that all the alloys
above 10-5 per cent. Al are harder than corresponds to a linear
relationship between hardness and composition, probably due
to the mutual support offered by the two constituents in the
eutectoid. It is also of interest because Andrew (be. cit.) considers
that the reason that the alloys containing less than 11 per cent. Al
94 Greenwood : The Constitution of the Copper
are softer on slow cooling than on quenching to retain the S
solution is, that the soft nature of the a has a preponderating
effect on the hardness determination. These results show that
this is not so.
The structures of some of these a -{- 8 alloys are shown on
Plate II. In No. 10 (10 per cent. Al) the network is the eutectoid
and the structureless part the a solution. In No. 11 the alloy
(11-2 percent. Al) indicates a considerable increase in the quantity
of eutectoid. The 12-3 per cent. Al alloy (No. 12) shows that the
eutectoid point has now becai passed, for the thin dark boundaries,
as also the small idiomorphic crystals, are the 8 solid solution. It
must be remembered that these crystals have been deposited from
the /3 solution on cooling, and that therefore the symmetry which
they present may be that of the ^ solution. Even better defined
crystals are shown in the furnace-cooled alloy (13*3 per cent. Al),
Plate III., No. 13. The increased quantity of the S is very notice-
able, as also is the thickening of the boundaries. No. 14 also shows
the 13-3 per cent, alloy, but much more slowly cooled. In this
case the S has coalesced into large masses, there being no con-
tinuous boundaries such as those shown in No. 13. The beautiful
laminated form of the eutectoid is also well depicted in this
photograph. It is very interesting that there is practically no
difference in the hardness of the structures shown in Nos. 13 and 14.
This is important, as it has been contended that continuous bound-
aries of a hard constituent Uke the 8 solution, especially when
supported by a close eutectoid network, give a false hardness
value. No better refutation of this contention could be given than
this, for the respective Brinell hardnesses are 303 and 298.
The Hardness of Alloys Quenched at 600° C. after
Attaining Equilibrium.
Between 9*7 and 12 per cent. Al the alloys when quenched
at 600° C. consist of the a and yS solutions, the quantity of the
latter increasing with the percentage of Al until the 12 per
cent, alloy is pure yS. Between 12 per cent, and 16 per cent. Al,
on the other hand, the alloys consist of the /3 and 8 solutions,
the fi in this case decreasing as the Al increases.
Before making any hardness determinations the alloys were
subjected to a prolonged annealing in accordance with the data
Reduced by one-fifth.
Mo. 13.— Alios lUoo ■'•'<■ Slowly cooled.
Structure 5+eutectoid. Brinell hard-
ness, 303. Magnification 120 diameters.
77!f, f^, ■
No. 14.— Alloy 13-3% Al. Very slowly
coded. Brinell hardness, 298.
Magnification 120 diameters.
0.15.— Alloy 10-5% Al. W.Q. from 0 area.
Brinell hardness, 286. Magnification
60 diameters.
^f|i»^4
m
^
No. 16.— Alloy 110% Al. W.O. from &
area. Brinell hardness, 232. Mag-
nification 60 diameters.
.V^
17.— Alloy 12-6%A1. W.Q. from /8 area.
Brinell hardness, 175. Magnification
60 diameters.
ij*^
'- .W -
No. 18.— Alloy 110% Al. W.Q. from /3
area. Brinell hardness, 224. Mag-
nification 60 diameters.
I To face t>.
Alloy Vd'H pjr cent, aliiiniiiium.
Mm^i
No. 19.— Air coulcd from 8OOOC.
Annealed 9 daj'.s 550°. Brinell hard-
ness, 298 ; Scleroscope hardness, 66.
Magnification 60 diameters.
No. 20.— Cooled from 800^—500° in 1
hour. Annealed 9 days 550° C.
Brinell hardness, 298 ; Scleroscope
hardness, 66 "S. Magnification 60
diameters.
No. 21.— Cool.. i iiMin 80G°C— 500° in
12 hours. Annealed 9 days 550°C.
Brinell hardness, 29B ; .Scleroscope
hardness, 66-5. Magnification 60
diameters.
No. 22. — Same specimen as No. 19, but]
etched with ammonium persulphate!
and ammonia instead of ferric |
chloride and hydrochloric acid. Mag-
nification 60 diameters.
Rich Aluminium-Copper Alloys '
95
given on p. 80. All structures were examined in order to be
sure that the quenching had been carried out efficiently before
any tests were made.
The results of Brinell determinations are given in Table XXI.
Table XXI.
Aluminium per Cent.
Time Annealed at
600° C.
Structure.
Brinell (1500 Kg.).
9-7
13 days
a
4-86 76
100
14 „
a-)3
4-23 101
110
12
a + ^
3-61 140
11-7
12
a+ $
3-48 150
121
12
&
3-40 160
12-3
12
/3 +5
3-33 168
12-6
11
/3 + 5
315 187
13-3
11
/3 + 8
2-73 252
These values have been plotted in Fig. 11. It \sdll be noticed
that there is a marked deviation from a linear relationship between
hardness and composition, just as in the case of the a + S alloys.
The 13'3 per cent, alloy was the highest on which this test was
carried out, and the curve has been extrapolated beyond this,
assuming the hardness of the pure 3 alloy containing 16'0 per
cent. Al to be 368, as found from the series of determinations
made on the a + 8 alloys.
Summary and Conclusions.
The object of this investigation was to examine the rela-
tionships existing between hardness and composition in several
phase areas at the copper end of the aluminium-copper equilibrium
diagram.
Before this could be done satisfactorily it was necessary to
make a preliminary examination of the methods which were
to be subsequently employed. These included quenchings from
different temperatures of alloys of various compositions, and
determinations of the hardness of these specimens by the Brinell
and scleroscope methods.
Accordingly the effect of various factors on the results ob-
tained by these two instruments was first examined, and the
information obtained may be summarized as follows :
(a) With coarse structures consisting of two constituents
of wdely different hardness scleroscope tests must be made
I
96 Greenwood : The Constitution of the Copper
with great care, and the average of a large number of tests
taken. The effect on the Brinell is negHgible.
(6) For Brinell tests the specimens need not be thicker than
0-2 in. (if a load of 1^00 kg. is used), but with the scleroscope
the results are erratic with this thickness, but are quite consistent
Avith specimens of 0-4 in. and upwards.
360
^ 320
Q 280
oj 240
V>
<*: 200
^ 160
%
1
1
•
/
1
r
■^
^^"'"'•^
J
/
9 10 II 12 13 14 IS 16
%Al
Fig. 11. — Hardness of Alloys Quenched at 600° C. after reaching
Equilibrium.
(c) A wide variation in the smoothness of surface is allowablel
for the scleroscope tests.
{d) The Brinell hardness number increases with the load!
applied, but becomes comparatively constant with a load ofi
3000 kg. and upwards. There is a linear relationship betweeDJ
the hardness as obtained with a load of 1500 kg. and the corre^
spending hardness as obtained with a 3000 kg. load, the latteil
being obtained by multiplying the former by 1*06.
Rich Aluminium-Copper Alloys 97
A series of quenching experiments on alloys containing 8-7
to 13-3 per cent. AI was next done. These showed that the
ease with which the /3 solution could be retained varied enor-
mously with the composition, being easiest in the neighbourhood
of the eutectoid point and more difficult as the limits of its
existence were approached. The remarkable sluggishness of
these alloys was also brought out by these experiments, and lead
up to an inquiry into the time required for them to reach
equilibrium.
It was found that at 600° C. a period of twenty days was
necessary for the phases to arrive at an equilibrium by means
of diffusion. As a further result of these experiments it has
been found that an alloy containing 9-7 per cent. Al can be obtained
as the a solution. Hence the upper limit of the a solution range
must be moved from the 9*0 per cent, as found by Curry to the
neighbourhood of 9-7 per cent, as found by Carpenter and Edwards
and the present author.
The hardness-composition curve of the a solutions is found
to be linear, both by the Brinell and scleroscope. Hence the
idea that the upper limit of this series of solid solutions is formed
by the compound Cu^Al cannot be held.
On the other hand, the existence in the /S solutions of the
compound CU3AI receives confirmation, from the presence of
a minimum at the composition of the compound in the hardness-
composition curve corresponding with this phase.
The alloys consisting of the a + S mixtures depart considerably
I from a linear relationship with the composition when hardness is
measured by the Brinell method, in the sense that they are harder
than would be calculated from a linear equation. The same remark
applies to the a + /3 and yS + S mixtures.
In Fig. 12 the whole of the curves representing the relation-
ships between hardness (Brinell), and composition in the phase
areas considered have been assembled, so that the relative
hardnesses of different alloys, or of the same alloy with different
heat treatments, can readily be ascertained. Further, by com-
parison with the microstructures, the changes of hardness with
^ structure can readily be followed.
In conclusion, the author would like to point out that there
are so many interesting points about the ^ solution that it has
been necessary to make a separate investigation of it. Hence
VOL, XIX. H
98 Greenwood : The Constitution of the Copper
\
(O^ 009/ o\/oi ) SSlNOyVH n3Nld9
Rich Alitminmm-Copper Alloys
99
the almost total absence of theorizing on this particularly
tempting subject. It is hoped that the results Tvill shortly be
ready for publication.
APPENDIX.
Kelationship between Brinell Hardness and Sclergscopb
Hardness in these AitpoYS.
At the commencement of this invest isjat ion it was the author's
, V ! I
• • \
•_ ij • \ 1
* X
• \
A^ ^
• \ • •
« \
— - - . ■ . . ■ ■ — • -V ■
•* \
•«\
^__ ___^ . «r ■
'~~ ~~~ \ »
<:i ''^ -2
(NO>f 009/) 9S3//oytrH nsNfyff
intention to use the scleroscope for the exploration of those
100 Greenwood : Akiminiuni'Copper Alloys
phase areas in which the alloys were too brittle to stand even the
lowest practicable Brinell load. But after some experience
had been gained in the usage of the instrument, it became
apparent that the readings were unreliable after a hardness
of about 50 had been attained. Accordingly it has been im-
possible to experiment on alloj^s containing more than 16 per
cent. Al.
The results which have been obtained with the two types
of instrument are plotted in Fig. 13, in which the ordinates
are scleroscope hardness and the abscissae Brinell (1500 kg.)
hardness numbers.
The very considerable deviations when the scleroscope hard-
ness is greater than 50 is clearly shown. Even below this there
are quite an appreciable number of observed points which fall
off the mean curve. It has been noticed, however, that such
points often belong to a definite series, e.g. the series of specimens
of alloy 10-0 per cent. Al quenched at different temperatures
lay on a straight line lying above the mean.
Discussion oiu Greenwood's Paper 101
DISCUSSION.
Mr. J. Neill Greenwood, M.Sc. (Manchester), in introducing liis
paper, said that there were two points to which he would like to draw
attention before the discussion proceeded.
The first was in connection with Fig. 1, in which the eutectoid
Hue had been drawn at 500° C. This had unfortunately been an
oversight on his part, in taking some of the data for the diagram
from Curry's work. Actually the equilibrium position of this hne
was between 550° C. to 570° C. He only mentioned this because
on p. 95 he had given hardness values of the alloys after attaining
equilibrium at 600° C ; i.e. just above the eutectoid transformation.
The second point referred to the surface finish used in the scleroscope
experiments on p. 67. He had omitted to say that the grades of
emery (0, 00, and 000) were Hubert's French emery papers.
Professor C. A. Edwards, D.Sc. (Member of Council), said that it
was his pleasure first of all to say how much he wished to congratulate
Mr. Greenwood on producing what was a really able account of a most
interesting and carefully conducted piece of work. In the paper
Mr. Greenwood kindly acknowledged that the work was suggested by
the speaker, but he thought all the members would agree that Mr.
Greenwood had formulated his own conclusions. He had conducted
the work entirely himself, and had not in any way been unduly in-
fluenced by any ideas or statements that he (the speaker) had made.
He did not propose to deal with or discuss certain sections of the
paper, because he had not had a proper opportunity of studying the
conclusions which Mr. Greenwood had arrived at. Perhaps he might
contribute a written discussion to the theoretical side later on. He
would like, however, to refer to some of the experimental details,
because he had in another connection been really interested in some
of the matters referred to and the exjjerimental methods adopted by
Mr. Greenwood.
First of all, he could fully endorse all that was stated in the paper
with regard to the variations in the Brinell hardness numbers obtained
with variations in the load applied. Those variations extended not
only within the range of hardness experimented with by the author,
but he might say that the hardness of all, or rather the curves for the
Brinell load-hardness numbers, varied with the hardness of the materials
something in the following way. As the hardness increased one had
to apply an increasing load to obtain the maximum hardness number,
^.e. the real hardness number ; and it was extremely difficult to know
just what load should be applied in order to get a really satisfactory
iO^ Discussion on Greenwood's Paper
hardness figure. That difficulty was very great. For instance, with
hardness of 100 Brinell one very quickly got the maximum value with
something of the order of 500 kg., but with hardness of anything like
the order of 700 Brinell one could not get a true Brinell number for
anything below a load of something of the order of 5000 kilos. So that
was a defect of the Brinell method which had to be very carefully
taken into account.
He was rather interested in the equations that the author gave
on p. 71, particularly because it would be seen that those equations
had nothing in common one with another. There again that showed
the different efiects which were manifest in those alloys in regard to
the efiect of cold work on the values obtained. If we could eliminate
the influence of cold work which was produced during the application
of the Brinell load, we then ought to be able to get a true intrinsic
hardness value. If that could be accomplished it should be possible
to get a common expression for what he might call the load hardness
number, which would be the same for all materials, no matter what the
hardness might be. He did not wish to anticipate anjrthing which had
been found in connection with an investigation which he (the speaker)
had made. But he could say that by another method of hardness
determination one could get a time indication of the intrinsic hardness
of metals.
If instead of using a slowly applied static load one used an impact
load, then the diameter of the indent which was obtained, no matter
what the load might be, when using a 10 mm. ball, equalled a constant
times the fourth root of the energy applied. That rule was applicable
no matter what energy was applied. That being the case, the value
of the constant was ob\aously a true measure of the intrinsic hardness,
apart from the effect of cold work on metals.
That equation applied for all metals, no matter whether the
hardness was, say, 2 Brinell for lead, or whether it was the hardest
possible steel that could be obtained.
To indicate that cold work had a very varying efiect, he might
say that if two metals (such as tin and aluminium) were taken and
tested by the two methods, it would be found that tin under impact
was very much the harder, but by Brinell exactly the reverse was the
:ase, showing that one metal had a totally different capacity for cold
work from the other. They were the only two instances that he had
so far been able to detect. ^Yith these exceptions, one could calculate
from an impact measurement exactly what hardness number one
would get with the ordinary slow application of the load. That
brought him to the other question, viz. the scleroscopic measui'e-
ments. The chief objection to this instniment was that the height
of the hammer was constant in all cases, so that the energy applied
was always the same ; consequently the depth of penetration or degree
of work varied with different metals and of comse the energy absorbed
was different. Under these conditions the height of rebound was of
Discussion on Greenwood's Paper 103
course not a true indication of tlie liardness of the material. But it
should be possible to calculate the true hardness value from the height
of rebound on the scleroscope, if one knew the arithmetical relationship.
The work carried out by the author necessitated, if not a modi-
fication of his \dews, then his admitting that he was wrong in
certain directions. Many years ago he said that copper-aluminium
alloys hardened by quenching throughout the range of 9-16 per cent,
aluminium, but now he found that at and about the eutectoid com-
position they did not. But, as the author had intimated, that was
due to the compound which was at the root of the solution of the
eutectoid alloy, and that of course altered the whole question.
Dr. W. RoSENHAiN, F.R.S. (Member of Council), said that the
author was to be congratulated upon a very interesting contribution
to the study of one of the most puzzling systems of binary alloys which
metallurgists had been called upon to investigate in detail. The only
doubt one felt on reading the paper — it was not so much a doubt as
a regret — was that the author should have started at that end of the
work. He himself had evidently come to the conclusion, as could be
seen from the paper, that it would have been better and easier for
him, and easier for his readers, if he had begun by limiting the phase
fields more carefully than had yet been done before he began the
measurement of physical properties. The measurement of hardness,
at any rate as it had been measured hitherto, in the absence of the
new methods which had just been foreshadowed, did not appeal to
one as the best method of investigation for the purpose of studying
the structural constitution of alloys. He would have thought that
such a method as that provided by electrical resistance measurements
would have ofiered a more definite and direct set of results with
regard to the phase fields, if physical methods were required, as
no doubt they were, to supplement thermal and microscopic data.
The very difiiculties of the hardness measurement as it stood at the
point where the author took it up were evidenced in the paper itself.
For that reason he would suggest that the somewhat final form in
which the author stated his view that the compound copper-aluminium
(CU4AI) did not exist, because there was no corresponding deflection
in the hardness curve, was possibly a little premature. One could not be
quite certain that the compound did not exist, simply because the
shape of that hardness curve did not appear to indicate it. It was
always a little dangerous to generalize from measurements of one
quantity, even if those measurements were correct. In the present
instance the measurements were not particularly accurate, and the
physical property was perhaps one of the vaguest which had to be
dealt with.
There were one or two special points in the paper which he thought
were worthy of notice : first of all, the point that the distribution
of the constituents did not appear to affect the hardness. There
104 Discussion on Greenwood's Paj>eY
was sometliing very wrong there somewhere. He was not disputing
or doubting the author's observations, but the conclusion was at
remarkable variance with one's definite knowledge of the behaviour
of steels in that particular matter, and those alloys in their physical
properties were very similar to steels. It was well known that if a
pearlitic steel were annealed in such a way as to destroy the pearlite
and to replace its lamince by scattered globules, a very marked lower-
ing of the elastic limit resulted, and this, no doubt, was accompanied
by a reduced Brinell hardness. That was well known in practice, and
its disastrous results had been repeatedly experienced. He would
be interested to know whether the negative result which the author
had obtained, finding no difierence between a coarse and a fine structure
of the same kind, was applicable also to a measurement of the elastic
limit of that alloy. Was there, or was there not, a softening of the
alloy due to the segregating effect of the treatment as measured by the
elastic limit, even though there might not be when measured by the
Brinell hardness ? It would be interesting also to see that conclusion
tested in the alloys in cases where the quantity of the second con-
stituent was very much smaller, so that one really obtained isolated
patches of it instead of merely a coarse duplex structure difiering
in scale but not very much in pattern from that of the untreated
alloy.
There were one or two minor points to which he would like to
refer. On p. 80 the author made a statement which he would be
glad to have explained a little more fully. He did not quite under-
stand what the author believed to happen. The point related to the
question of the very gradual change in hardness which occurred on
prolonged annealing in certain of the alloys when the microstructure
apparently had been rendered homogeneous, but the hardness continued
to decrease by further annealing. Now the author ofiered an explanation
which to him was rather incomprehensible, because he said the result
of the gradual difiusion of the one constituent into the other was the
formation of a supersaturated a solution. He thought it would require
a good deal of justification to suggest that diffusion could produce a
supersaturated solution. He was inclined to think that most physical
chemists would agree in saying that this was the last thing in the world
which diffusion could bring about. The question arose. How was the
fact observed by the author to be explained ? Did it really mean tliat
because prolonged heating at that temperature, after microscopic
homogeneity had been attained, would produce a change of physical
properties, there was still a change of constitution going on ? He
was inclined to think that it did not mean that. The explanation
he would suggest was that the rearrangement of the crystals and the
absorption of what he would describe as amorphous intercrystal layers,
and possibly even of amorphous layers within the crystals arising
from the rearrangement which diffusion brought with it — that it was
that gradual absorption of those layers which reduced the hardness
Discussion on Greenwood's Paper 105
during prolonged annealing. He thouglit there was a great deal to be
said for that view, and he would suggest it to the author's consideration
as perhaps preferable to the one which he had put forward.
On the subject of hardening by quenching which had been raised,
he thought the author had again made a statement which required at
least an explanation, on p. 88, where he said : " With regard to the
second effect of quenching, namely, the retention in a state having
a difEerent volume from the stable state, this can only act in one way.
That is to say, the greater the specific volume the lower the hardness
value. This follows from the fact that the greater the distance between
the molecules or molecular aggregates, the smaller the mutual attraction
of the masses, the forces being inversely proportional to the square
of the distances apart." To begin at the end of that statement, he
did not think that the author, or any other person at the present
moment, was able to say what was the exact law of intermolecular
attraction. Whether it varied inversely as the square or any other
power of the distance, he thought the molecular physicists would not
be prepared to state definitely.
He would draw attention to the fact that when metal was hardened
by cold work its density was reduced — not very much, but it was
reduced none the less — so that with a higher specific volume and the
same chemical constitution, the metal was harder and not softer.
He thought the whole of that argument required very careful and
considerable revision.
He hoped that the author would understand that his critical doubt
arose out of a very thorough appreciation of the value and interest
of the work which he had done.
Dr. 0. F. Hudson (London) said that he was sorry he had not
had time to read the paper as carefully as it deserved. The author
had given a record of a large amount of very useful and careful work.
Perhaps the most interesting point was the promise by the author
that in the near future he would bring forward results of researches
dealing with the constitution of the ^ phase in the system ; in fact,
any researches on the constitution of the solid solutions would be
of the very greatest value. He had one point in mind on which he
intended to offer some criticism, but that had already been dealt with
by Dr. Rosenhain. The point was the decrease in the hardness due to
prolonged annealing, and the explanation given by Mr. Greenwood
that it was caused by the gradual diffusion of the /Sand the a solutions.
The explanation given by the author might be correct, but it appeared
to him that it had not been conclusively proved. WTiat was proved
was that the hardness decreased, but that that decrease in hardness
was due to the want of homogeneity in the a solution he thought was
still open to some doubt. So far as his own experience went, suitable
etching methods were an extraordinarily delicate means of showing
lip any slight differences in composition in solid solutions, and he
106 Discussion on Greenwood's Paper
would like to ask the author if he had tried other methods of etching
to determine whether micrographically the alloys were homogeneous ;
also if the author had determined whether a pure a solid solution,
one that was originally a and contained no fi at any time, on pro-
longed annealing showed any corresponding or any similar decrease
in hardness. That was a point which he thought should be cleared
up, because it appeared to him possible that even a pure a solution
might on annealing perhaps show a decrease in hardness of a similar
order, due to some crystalline rearrangement.
Professor T. Turner, M.Sc, Vice-President, said that he noticed
that in his first conclusion the author mentioned that the effect on the
Brinell tests of coarse structures, consisting of two constituents of
widely different hardness, was negligible. He thought that arose
from the size of the grains of the constituent of the samples that he
tested ; because, as had already been at all events hinted by Dr.
Rosenhain, in other cases somewhat different results had been obtained.
If, for instance, one annealed a sample of duplex brass and had a
portion of a harder constituent side by side with the softer, and then
took a Brinell test, including both constituents, the softer material
gave a larger and rounded part of the impression, while the harder
material gave a smaller and a rougher indentation. The difficulty
was to determine what was the true diameter of that impression,
because measured in one direction it was longer than if it were measured
in the other. If a duplex structure were taken there might be cases
in which the Brinell test would give different results in one portion
as compared with the other.
The author had given the hardness curve in Fig. 8 of an a solution,
and in that case the curve was a straight line. That was a matter
which was emphasized by the author, not only in the letterpress,
but also in the other curve in Fig. 12.
As a rule a solid solution did not give a straight line — ^it was generally
a curve ; so that the case he had just mentioned must be regarded
as exceptional. But it might be pointed out that there were other
cases which must also be regarded as exceptional, in which the physical
properties, as, for example, the limit of elasticity, or the reduction
in area — i.e. the ductility — instead of falling to a minimum might
give nearly a straight line throughout the series. That was found,
for example, in nickel steel. While the ultimate strength rose with
increase of nickel the ductUity fell, but very slightly, and gave nearly
a straight line. The case he had referred to was therefore an interesting
example of what might be regarded as somewhat exceptional, though
it was by no means unparalleled. Perhaps from the point of view
of the discussion of hardness as apart from the question of constitution,
the most interesting point that had been raised in the paper was the
effect of cold work upon the samples, depending upon the variations
in the hardness of the materials employed, and upon the load that had
Discussion on Greenwood's Paper 107
been used. It was well to realize that tlie Brinell test, admiiable as
it had proved itself in practice, particularly to the kind of material
for which it was originally intended, namely, for a homogeneous and
mild steel, was imperfect if one endeavoured to compare the results of
soft materials which were considerably displaced with those of hard
materials in which the amount of work was comparatively small.
It was also interesting to see that similar results were obtained with
the scleroscope, and he did not think it was divulging any secret when
he said that Professor Edwards was studying that subject somewhat
fully, and had a paper in course of preparation which would shortly
be published and which brought out some interesting further points in
connection with the subject.
He did not know that it was of great practical importance so long
as one confined oneself to one kind of material, such as brass or steel,
but theoretically it was a matter of very high interest, enabling one
to understand more perfectly what one meant when one spoke of
hardness, and the difference between hardness as measured statically
and that which had been determined by dynamic methods.
Dr. W. H. Hatfield (Sheffield) said that he had read the paper
with considerable interest, and would like to congratulate the author
upon the manner in which the work had been conducted and upon the
deductions which he had drawn.
On the question of the determination of hardness, which was one
in which everyone present was primarily interested, he felt, as Professor
Edwards was speaking, that if the Professor was not careful he might
be measuring something which was somewhat different from hardness
as generally understood, and as those present wished to obtain it for
the pm-poses for which they were employing that property.
The author had endeavoured to correlate the resiilts obtained
from the Shore and the Brinell. He (Dr. Hatfield) had been trying to
do the same thing, and with precisely similar results. Yet he noticed
the author had drawn a line through the Shore results, and by doing
so he rather " gave the show away " ; the drawing of the line indicated
faith in a relationship. Personally, he thought there was some relation-
ship, but other factors besides the mere tensile strength of the material
would have to be taken into consideration. Speaking of the Shore,
he wanted to mention a most interesting fact. His physicist, Mr.
Stanfield, came to him about a month ago and said : "I have noticed
a most curious thing ; in using the Shore scleroscope I find apparently
that the hammer tires — that is, if you go on using it the reading actually
changes." He had paid considerable attention to that point, and was
able to confirm the fact that the Shore determination actually varied,
i.e. became slightly lower, if one went on using the instrument. They
were doing further work relating to the matter, and he did not want
to go into too much detail at the present moment, but it seemed to
him to be an extremely interesting subject. v .
108 Discussion on Creenwood^s Paper
Professor Edwards said that was why he wanted to confirm it.
He would like Dr. Hatfield to make it clear whether the hammer was
repeatedly falling on the same spot or on different spots. That was
very important.
I
Dr. Hatfield said it fell on different spots.
Professor Edwards inquued whether it was a diamond or a steel- 1
pointed hammer.
Dr. Hatfield replied that it was a diamond-pointed hammer.
He would be interested to know also whether any other worker had
had a similar experience.
He was also interested in the two micrographs, Nos. 13 and 14
(Plate III.). He was not throwing any doubt on the author's determina-
tion, but it was of fundamental importance, because if the micro-
graphs were correct, with the same Brinell hardness as was shown
there, and if it could be demonstrated by the Shore test, which was
largely dependent on the elasticity of the material, or, by determining
the true elastic limit, if it could be shown that with such variable
structures diverse hardness was not obtained, he thought it would be
a very severe blow to Dr. Thompson's surface-tension theory, on
which personally he had an open mind. He thought it was one of
those theories which did in a general way fit in with most of the facts
as known at present, but he felt that if the author established the facts
the theory would be greatly weakened. Therefore, owing to its im-
portance, he hoped a few more detailed determinations on the material
might be given.
Mr. Greenwood, in reply, said that, with regard to Professor
Edwards's remarks upon the method of testing hardness which he had
recently worked out, he had little to say, because as yet he was not
fully conversant with Professor Edwards's results. But from what
he knew of the method he did not quite agree with Professor Edwards
that he entirely eliminated cold-work effects ; in fact, he could not
see, if an impression was obtained at all, how by that method of testing
one had eliminated the efiects of making an impression. The only
way he could see of getting rid of it was not to make an impression.
That might seem rather an impossible thing, but there was a possible
way of getting round it, namely, by taking a Brinell impression, then
annealing the specimen and taking another Brinell impression in tlio
same hole ; a stage woiild ultimately be arrived at when the area of
the impression was just sufficient to support the load without further
deformation. The (Brinell) hardness number was the load in kilo-
grammes divided ])y the area of the impression, so that one simply
got as an expression of hardness the pressure per square millimetre,
which the metal would stand without further deformation. Therefore
Author's Reply to Discussion 109
when tlie impression was just sufficient to support the load applied
without any further deformation, that was the only way of getting
rid of cold work, and the only way in which the true (Brinell) hardness
number could be obtained. With regard to the hardness of the /3
solution referred to by Professor Edwards, he thought Professor
Edwards let himself off rather lightly when he drew attention only
to the point of an alloy of eutectoid composition being softer in the
quenched state than in the segregated state. He thought the curves
(Fig. 12) showed that most of the alloys were softer, at any rate that
all the alloys above 11 per cent, were softer when they were in the
quenched state than in the segregated state. It seemed to him there
was no reason why there should be any connection between the hard-
ness of the ft solution and the corresponding a -|- 8 mixture. With
regard to Dr. Rosenhain's point on the question of the method he
(the author) had chosen for making physical measurements, namely,
by means of the hardness test, he might point out that primarily the
object of the work was to settle various points of difference which had
arisen between Professor Edwards and other people on the effect of
quenching, so that he was simply led to the method of making hardness
determinations, and it resolved itself into the present paper. He
was interested in Dr. Rosenhain's calling attention to the fact that
there was no absolute proof of the absence of CU4AI in the a solutions.
That must remain open until other physical determinations
were made. He could only point out that it seemed highly probable
that the compound was not present, because it seemed peculiar that
a method of determining the presence of such compounds, which had
been shown to give definite types of hardness curve under test con-
ditions, had not given it in the present case ; at any rate, it pointed
strongly in the direction that the compound was not present. Of
course one had always to be prepared for what was not on the surface.
With regard to the doubt which had been thrown upon the effect of
segregation on the hardness, he quite saw the fundamental importance
of that point, and that was why he referred to it in the paper, but he
had not had anything like the time which would be necessary in order
to investigate such a point very closely. He simply referred to the
fact in the hope that perhaps other people might be able to do some-
thing in that direction. As Dr. Hatfield had definitely asked for
further information on that point, he would attempt to get some more
results and communicate them in the written discussion.
On the question which Dr. Rosenhain and Dr. Hudson had brought
up, as to the effect of annealing aluminium- copper alloys, the con-
clusion that the softening caused by prolonged annealing (after the
alloys were microscopically homogeneous) was due to diffusion of
aluminium from, and final break up of, the ^constituent, was arrived
at as follows. As the members Imew, alloys containing more than
8 per cent, of aluminium on casting contained small quantities of the
/? constituent. The original structure consisted of a mass of a, in
110 Author's Reply to Discussion
wliich were embedded small areas of eutectoid composition. He
found that on annealing at 600° C. this constituent disappeared and
the alloy became apparently pure a.
The eutectoid areas contained about 12 per cent, aluminium, and
so, assuming that an 8'5 per cent, aluminium alloy was under discussion,
the a areas must contain less than 8'5 per cent. In the natural process
of annealing he took it that the only way in which the eutectoid areas
could be converted into a areas was by diffusion of aluminium from
the richer to the poorer portions. In the equilibrium state the whole
of the alloy would consist of a solid solution containing 8"5 per cent,
aluminium, and in the passage of the eutectoid areas (containing 12
per cent.) towards the stable state, it seemed to him that these must
pass through a stage when they contained less than 9'7 per cent,
aluminium. At this point the original rich areas would have now
become a solution, but they would still be supersaturated with respect
to the stable state, towards which they were tending. Further annealing
would cause the diffusion to continue until ultimately the whole was
homogeneous a solution in a state of equilibrium.
With regard to the hardnesses, it was only in the cases of those
alloys which contained /3 before annealing that he obtained softening.
The hardness curve of the a solution as he first obtained it was as
A, Bj, Ci in Fig. 14, with a break occurring when the alloys had
previously contained the (3 solution. On annealing, the hardness values
for the three alloys containing 81 per cent., 8"7 per cent., and 97 per
cent, aluminium were removed from curve Bi, Ci, successively on to
Ba, Cj, and (after seventeen days' annealing) B3, Cs- He took it that that
was due to the diffusion taking place, because in those alloys the
retention of the /3 state caused an increase of hardness, as shown by
the curves in Fig. 5.
With regard to Dr. Rosenhain's remarks on the specific volume
and the effect of cold work on the hardness, he could only point out
that in the cases where hardening was accompanied by cold work, along
with an increase of specific volume, there was a definite new modifica-
tion which appeared, an amorphous modification. At least that was
said to appear, and so the case was not parallel.
Dr. Hudson had asked, in respect of the delicacy of the etching
method, whether he had used any other etching agent than hydro-
chloric acid and ferric chloride. In reply to that he must say that
he had tried several etching agents, including hydrogen peroxide,
ammonium persulphate, ammonia, and several others, the constituents
of which he did not remember at present, because it was quite a con-
siderable number of months ago since he completed his experiments,
and other things had intervened in the meantime. But, as far as he
remembered, he did not detect any difference in the structure which
accompanied the changes of hardness on prolonged annealing.
With reference to Professor Turner's point as to the difficulty in
connection with the Brinell impression when one had large structures
Author's Reply to Discussion
111
consisting of soft and hard constituents, he need only mention that
in those cases on which he had worked there was nothing like that
relationship between the size of the Brinell impression and the harder
constituent. The hard constituent was always considerably smaller ;
he meant that the separate particles of the harder constituent were
always considerably smaller than the Brinell impression, and he there-
'^/20
05
:::
^ 100
«*:
^ 60
tJ3 60
A<
c,
-
/ Ci
CHILL
Cast
/ ^
/ '' *
Annealed
4 Days
/
/
/
/
/
»-'"' Ri Ri
/ C3
Ra
Annealed
17 Days
D3
6
Vo AL
10
FiQ. 14. — Illustrating Reply to Dr. Rosenhain and Dr. Hudson on Question relating to the
Effect of Annealing a Alloys which had contained ^.
fore took it that the size of the grain in that respect would not affect
the determination.
Replying to Dr. Hatfield, he could only say that he would endeavour
to get the information he had asked for regarding the Shore and Brinell
numbers of those alloys consisting of constituents distributed in various
ways. Dr. Hatfield's remarks upon the " relationship " between the
Shore and the Brinell hardness numbers were certainly quite amusing,
because it was his idea in drawing the line in Fig. 13 to show that there
was no relationship. Of course he could have left it open, but it
seemed to draw attention to the fact that one got remarkable deviations
from the mean.
IVi Communications on Greenwood's Paper
COMMUNICATIONS.
Mr. J. Neill Greenwood, M.Sc. (Mancliester), wrote, in further
reply to the discussion, that he wished to express his sincere gratitude
to those members who had offered so much vahiable and useful criticism
of the work. It was obvious from the general trend of the remarks
how greatly interested metallurgists were in that " vaguest of physical
properties " — hardness. In fact, the preUminary experiments seemed
to have attracted far more attention than the subject proper. He
thought that this in itself was sufficient justification for the appearance
of the work in its present incomplete state.
^ He then referred to Dr. Rosenhain's statement, that " in the present
instance the measurements were not particularly accurate." If
Dr. Eosenhain meant that the test was not accurate, he agreed with
him. But the actual measurements and the experimental conditions
had been controlled with the greatest possible care. He did not
doubt that, with material ha%'ing a finer and more uniform structure,
more consistent results would be obtained, but he was quite certain
that the results in the paper were as accurate as the method (in this
particular case) would allow.
Several members — Dr. Hatfield in particular — ^had asked for more
information on the efiect of distribution of the hard and soft con-
stituents on the hardness test. He was now able to give the results
of some further experiments which he had carried out on the 13*3
per cent, aluminium alloy. He had not been able to make determina-
tions of the elastic limit as Dr. Rosenhain had suggested, but scleroscope
hardness had been taken along with Brine 11 hardness.
Three pieces had been used for these experiments, and they were
treated as follows :
(1) Heated to 800° C. and air cooled (40-grm. specimen).
(2) „ ,, and cooled to 500° C. in one hour.
(3) ,, ,, and cooled to 500° C. in twelve hours.
All three pieces were then annealed at 500° to 600° C. for nine
days in order to allow them to approach equilibrium. The structures
after this annealing were shown in Plate IV., Figs, 19, 20, and 21.
A series of ten scleroscope readings was taken from each piece, and
all the rebounds are given in the table on p. 113,
Afterwards the specimens were examined with a low-power lens
to see where the hammer had struck in each case. In the last column
was given the number of blows in which a hard S boundary had been
struck.
The agreement of the averages for the three structures was truly
remarkable.
Communications on Greenwood's Paper 113
Tkree Brinell impressions were then made on each piece (load,
1500 kg. Time of appUcation of load, 30 sees.). The results were
given in the second table, and they confirmed the scleroscope figures.
Although these results fully confirmed those which had been given
in the paper, beyond showing that continuous boundaries of a hard
constituent did not give a false value to the Brinell and scleroscope
Scleroscojye Results.
Alloy, 13-3 per Cent. Aluminium.
Treatment.
Rebounds.
Air cooled, 800= C.
One hour, 800= to 500= C. .
Twelve hours, 800= to 500= C.
66, 64, 66, 66, 65, 66, 65, 67, 69, 67
66, 66, 66, 63, 67, 68, 67, 66, 70, 68
66, 66, 66, 68, 65, 67, 68, 66, 68, 66
Average.
No. of
Boun-
daries
struck.
66
66-5
66-5
5
6
3
numbers, he was not prepared, on these few results, to base any
generalizations. The subject was so fundamentally important, from
a physical point of view, that he thought it was worthy of a detailed
investigation. Moreover, it was exceedingly difficult to get the 8
constituent of the eutectoid to divorce. After five days' annealing
just below 500° C. he had obtained a certain degree of coalescence,
Brinell Results.
Alloy, 13-3 per Cent. Aluminium.
Treatment.
Brinell Numbers.
Average.
Air cooled from 800= C
Cooled in one hour, 800° to 500° C. .
Cooled in twelve hours, 800° to 500° C. .
300, 296, 300
300, 296, 298
298, 296, 300
298
298
298
but there was practically no corresponding change in the Brinell
hardness.
He was very interested in the observation made by Dr. Hatfield,
that the scleroscope became fatigued if used long enough continuously.
He thought that those who had used the scleroscope much would
appreciate the patience of anyone who could fatigue the instrument.
Personally, he found that the operator was the first to suffer from that
complaint. He would, however, welcome any further information
on this very important matter.
VOL. XIX, I
114 Communications on Greenwood's Paper
Dr. J. H. Andrew (Manchester) wrote that lie wished to congratulate
Mr. Greenwood on his excellent paper.
Mr. Greenwood appeared, however, to have gone into great detail
with regard to the question of hardness, without first of all satisfying
himseU or others that the constitution of those particular alloys with
which he concerned himself had been correctly determined.
Although hardness determinations were a valuable help in arriving
at the constitution of any series such as that dealt with, they should
be taken rather as a confirmatory measure than as a final means of
determining the co-existing phases.
If he (the author) would carefully examine the thermal curves in
his (the writer's) paper referred to * he would assiu'edly be struck
with the incompleteness of our knowledge in this direction, particularly
in the neighbourhood of the ft range. The writer, owing to circum-
stances over which he had no control, not being able thoroughly to
work out this system as he would have wished, had to leave it in a
state of incompleteness.
From his (the writer's) curves the transformation ^-> a -)- 8
appeared to be no simple one. Cooling curves indicated the varia-
bility of the eutectoid transformation, this change occurring at 530° C.
in alloys containing between 10 and 11 per cent, aluminium, whereas
with 11*5 per cent, aluminium two points were obtained, namely, one
at 518° and another at 480°. The 12 per cent, alloy showed only one
point at 540°. With aluminium between 12-5 and 14 per cent, the
double change again occurred, the upper point being in the neighbour-
hood of 506°, and the lower one, as before, at 480° C.
Although there seemed to be little doubt that this variation in
transformation temperature and doubling of the point was due to
metastability of the system, details stiU required to be worked out.
Moreover, the low temperatiu'e change at 302° was still very incom-
pletely investigated.
If the author had concerned himself with these matters a little more
instead of adopting the role of critic and seeking for clerical errors in
the writer's other paper, f his time would have been better spent, and
he might have arrived at a suitable conclusion to explain the as yet
unknown.
The paragraph referred to by the author in his (the writer's) paper
was hopelessly wrong ; how this arose he (the writer) was not aware,
not having by him the corrected or (as the case may be) the uncorrected
proofs.
The deduction made by the author, however, that because of
these hopelessly contradictory statements the hardness values are
incorrect, was amusing, and to say the least, hardly a scientific
deduction.
The writer did not agree with the author's hypothetical curve,
* Journal of the Institute of Metals, No. 1,1915, vol. siii. pp. 2C4 -6.
•f Zeitschrift fiir Melallurgi'., _
I
Commimications on Greenwood's Paper 115
Fig. 2. In the case such as the one here dealt with, if A was a highly
malleable constituent and, B a hard brittle constituent, such a curve
might hold as long as B was not in great excess. As soon as B increased
to such an amount when the state was arrived at, where the B crystals
touched one another, a complete skeleton of B would be formed, and
the hardness value would be that of piu-e B or nearby. The hardness
value would then show a certain increase and sudden point of inflection
in the curve.
Again, the author adopted rather a curious method in his attempts
to produce what he styles as a plus 8 conglomerates. Surely a
soaking at 1000° C. for one hour followed by a slow cooling down to
500° C. was hardly the most suitable treatment for producing equili-
brium of two phases which might, as the writer's thermal curves
suggested, only be completely deposited from solution at a temperature
of 480° C. Would not a prolonged anneahng at 450° C. or so have
been the better means of attaining this object.
Moreover, the soaking at 1000° C. might easily oxidize the alumin-
iujn, or aluminium rich constituent, so as to deplete the quantity of
that element in the resulting product. This might possibly account
for the author's smooth curve shown in Fig. 10.
Another point in the author's paper that he (the writer) could not
understand was this. The author in his niicrostructure of a plus 8
invariably showed the delta constituent as etching up black, whereas
the writer invariably foimd this constituent to be of a beautiful
pale blue colour. The question arose therefore, as to whether the
author's or the writer's specimens were in a state of true equilibrium.
Was it possible that they had been working on entirely different pro-
ducts ? Judging from the photomicrographs, the author appeared to
have been dealing with a conglomeration of semi-decomposed /3 plus a
eutectoid of a and 8 constituents.
The writer would Hke to put the question to Mr. Greenwood as
to what colour the 8 constituent appeared in the eutectoid itself.
Judging from the photomicrographs included, it would appear that in
this state the 8 constituent was of a light colour, possibly the pale blue
found by the writer.
The curve given in Fig. 8 showing the increase of hardness of the
a constituent, as also that in Fig. 6 showing the time required
by the alloys to reach equilibrium, lent considerable support to the
theory advanced some time ago by Professor Edwards on the theory
of solid solutions, in which the latter stated that the identity of a
phase in solution was always preserved — that is to say, although the
microstructure throughout the a series may have appeared to be
perfectly homogeneous, molecules of the P constituent co-existed
along with the molecules of another constituent, say copper, throughout
this phase. If this was the case, an annealing of the a solid
solution, at a temperature of 4.50° C. or so, might show a change in.
hardness, the ^ constituent in solution became transformed at this
lie Communications on Greenwood's Paper
temperature into a phis S, the alloy at the same time assuming under
the microscope complete homogeneity.
It would be extremely interesting if Mr. Greenwood would carry
out a few experiments in order to test this.
The author's curve, Fig. 3, showing the variation in Brinell hardness
with applied load, was extremely interesting, as was also his deduction
that the constant in his equation might represent the hardening efiect
due to cold work. Why, though, should this constant vary for different
alloys ?
That this contention might be correct is shown up even better
^
^
^
y
^
y
/
^
/
/
/
/
^
■^
/
/
/ /
/ /
/ /
-^
//
//
500 /OOO /SCO 2000 2500 3000 3500 4000
LOAD /N KnOCRAMS
FiCx. A.
by plotting diameter of impression against load. Tliis had been done
in the accompanying figure (Fig. A), the upper curve being the values
given in Table X. for the 8-5 per cent, aluminium alloy, and the lowef
curve for the 13'3 per cent, alloy.
Plotted in this way it would appear that the harder the alloy the
less this constant, measured in diameters of impression. If it was
considered that the bigger the impression, the greater must be the
amount of cold work done, then at the same time the softer would be
the alloy.
This strongly pointed to Mr. Greenwood's hypothesis as being
correct. The fact that rather went against this theory was that the
Communications on Greenwood's Paper 117
Brinell test as iibually applied with low loads was supposed to give a
more correct figure for soft metals tlian for liard ones, wliereas ou the
basis of tliis theory the reverse should be the case.
This might be an incorrect way of looking upon this question,
but the writer merely offered this as a tentative suggestion, and invited
IVIi'. Greenwood's remarks. ,
Mr. J. L. Haughton, M.Sc. (Teddington), wrote that he had read
Mr. Greenw^ood's paper with very great interest. He considered that
the comparative study of the Brinell and scleroscope methods con-
stituted a most valuable contribution to the vexed question of hardness
measurements. He was, how^ever, very surprised at the statement
made on p. 66 that scleroscope tests on specimens of 0'2 in. thick and
under are unrehable, and would like to ask the author whether the
specimens were held in the vice provided with the apparatus for the
purpose of gripping thin specimens. He was especially interested in
this point, because recently he had occasion to measure the hardness of
a large number of pieces of thin steel plate about 0-1 in. thick. These
were held in the vice, and the results obtained were less irregular than
those given by the author. For example, in Table V. the mean diver-
gence from the mean for the 0-2 in. specimens is 7, and in Table VI.
it is 5. In the case of a series of ten measurements on one of the
steel plates just referred to, having approximately the same hardness
as that given in the above tables, the following results were obtained :
32, 33, 33, 32, 33, 35, 33, 31, 32. 32.
In this case it would be seen that the mean divergence from the
mean was only about 0-8. For another plate, having a hardness of
about 20, the divergence figure was approximately the same, while in the
case of yet another whose scleroscope number was 82, the figure was 2-1.
These figm-es seemed to suggest that either the 0-2 in. sections of the
aluminium-copper alloys would have given much better results had
they been held in the vice supplied with the instrument, or that it was
possible to get much more uniform results with the instrument in
question on steel than on — at any rate — aluminium-copper alloys.
If the latter were the true explanation it did not seem possible .to
account for it on the groimd of the microstructure, for both in the
case of the aluminium-copper alloys, and of the second of the steels
just referred to, the structure was of the same type, i.e. martensitic.
There was one other point to which he (Mr. Haughton) would like
to refer, and that was the question of the transformation velocity of
/8 into a and into 8. It was stated that the reactions increased
enormously in velocity as the composition departed from that of the
eutectoid. But as the transformation took place at higher temperature,
the more the composition departed from that of the eutectoid, was it
not reasonable to suppose that the increased reaction velocity was
118 Communications on Greenwood's Paper
merely due to the increase of molecular mobility with the rise of
temperature 1
Dr. F. C. Thompson (Shefi&eld) wrote that Mr. Greenwood was
to be sincerely congratulated upon presenting a paper which con-
stituted a real g^ddition to scientific Imowledge, not only with regard
to the alloys of copper and aluminium, but also to the question of
hardness in general and its determination.
Concerning the work done on the alloys themselves, he (Dr. Thomp*
son) had only one suggestion to make, namely, that, from some points
ARDNESS CONSTANT
A
/
/
/
y
/
^ 20
/
a/®
/
.
5 10 IS 20 25
Yield Po/nt (tons per Sq. /n.)
Fig. B.
30
of view, the electrical conductivity method offered certain~advantages
over hardness determinations in such a research. Thus the electrical
conductivity was susceptible of distinctly more accurate determination
than was hardness, and, further, it was concerned with the specimen
as a whole, and was thus less Uable to error in coarsely segregated
samples than was a hardness measurement, according to the exact
spot selected for the determination. It would be of considerable
interest if a series of conductivity determinations made on the same
alloys could be pubUshed.
The real point with which he wished to deal was in connection
with the very useful and careful work done on hardness measurement
in general.
Communications on Greenwood's Paper 119
In many respects the conclusions arrived at in tliis paper were
similar to those of Mr. W. N. Thomas, published in the paper referred
to by Mr. Greenwood. It was, however, of interest to have the con-
clusions checked, especially as the previous work had dealt exclusively
with ferrous material.
On p. 71 was collected in the form of equations the work done on
the relationship of the Brinell hardness to the force applied, and the
most interesting conclusion was arrived at that the Brinell hardness
of each material was the sum of a constant and of a figure which was
a function of the pressure apphed, H = K + I*"^- The result appeared
to be somewhat surprising to the author of the paper, who had extra-
polated all the curves in Fig. 3 back to the origin, thus omitting the
constant completely.
There did not appear, however, to be any satisfactory reason why
the curves should pass through the origin. At that point, i.e., under a
zero load, a zero impression would be made, but, since the hardness
was defined as the ratio of the pressure apphed to the spherical area
of the indents, the hardness under no load was the ratio of two zero
quantities, which was of course an indeterminate quantity, hut not
iiecessarily zero. Thus the constamt term in the hardness was to be
expected rather than otherwise.
With regard to this term, Mr. Greenwood suggested that it "repre-
sents the hardening effect of the cold work which necessarily
accompanies the test."
A consideration of the facts, however, suggested an alternative,
and, as he beUeved, a much more satisfactory explanation. The
factor which was due to the hardening of the metal as a result of the
deformation was much more hkely to be the P-^, which depended on
the pressure apphed, and increased with it. The constant was then
left as the true hardness of the material before deformation occurred.
When in the Brinell test the ball was first apphed to the sample
the area in contact would be very small, and essentially plane. The
stress set up was therefore a direct compression, and the resistance
to penetration would be the real hardness of the undeformed metal.
When the elastic hmit of the material in compression was reached,
work hardening would ensue, and only then would the term P*^ com-
mence to exert its influence. One was therefore led to believe that
the constant would be a measure of the true elastic hmit of the
material for compressional stresses.
The paper contained no data from which this conclusion could be
checked, but on referring to the Eighth Report to the Alloys Research
Committee the yield points in tension of some chill castings of similar
composition were to be foujad. For normal metals and alloys the
elastic hmits in tension and compression were practically the same.
These results were given in the table, and it would be observed that
the order of the yield point and the constant term was the same.
When plotted against each other these factors gave a practically
120
AutJior''s Reply to Commimications
straight-line curve (Fig. B., p. 118), which confirmed the relationship
of the constant to the elastic limit suggested.
Percentage of
Alumiuiutn.
Con£tant.
Percentage of
Aluminium.
Yield Point.
8-7
9-7
100
12-6
13-3
35-5
37-2
38-9
490
83-2
812
9-38
9-9
11-73
130
9-7
10-5
10-5
U-8
2;.-U6
Mr. Greenwood's results thus lead to the very interesting equation :
Brinell hardness = a constant, which was a function of the elastic
limit of the metal, plus a term which was a function of the stress
applied, indicating the extent to which the material was hardened
by cold work.
This statement reversed the meaning which Mr. Greenwood had
given to the two terms.
Mr. J. Neill Greenwood (Manchester), replying to the written
discussion, wrote that he was very interested in the points which had
been raised, and wished to thank those gentlemen who had helped to
make the work much more interesting to himself, by reason of the
alternative explanations which they had ofEered.
Dr. J. H. Andrew appeared to have read meanings into his state-
ments which had never been intended in the original, and which con-
sequently could not be foreseen. He thought that Dr. Andrew had
been a little premature in his more or less wholesale condemnation
of the work, and that a more careful reading of the matter contained
in the paper would have rendered unnecessary most of the first half
of the contribution. For example, he wrote that he did not agree
with the author's hypothetical curve in Fig. 2, but as stated on p. 62
this was a graphical representation of Dr. Andrew's quoted statement !
Reference to photomicrographs 13 and 11, Plate III. (to which atten-
tion was particularly draAATi on p. 94), should have dispelled the false
idea of the efiect of continuous boundaries of a hard constituent, even
if the curve in Fig. 10 was unconvincing. He (Mr. Greenwood) would
point out the further results which had been communicated in reply
to Dr. Hatfield.
He did not see anything peculiar about the normahzing treatment
to which he had subjected certain specimens. It seemed to him that
the surest way of obtaining final equilibrium was to keep the solutions
in equiUbrium during cooling. Naturally, difiusion was much quicker
the higher the temperature, and at 600° C. the rate of diffusion as
shown by the data given was very slow. Annealing at 150° C. would
take at the very least several months in order to obtain equilibrium.
Author's Reply to Communications 121
Tlie thermal curves referred to were no criterion at all, since it was not
likely that the rate of cooling had been anything of the order of 500° C.
in two days. Great care had been taken to prevent oxidation — an
obvious precaution. However, certain specimens (of which the hard-
ness values did not appear in the paper) had accidentally become badly
oxidized, and it was found that the oxidation was greater the greater
the quantity of the S (or y) constituent. Hence if any oxidation
of the specimens mentioned had taken place, the efiect would have
been to straighten the curve in Fig. 10 and not to cause it to bend more
sharply, as suggested by Dr. Andrew.
There was no question as to the identity of the constituents in the
respective author's alloys. They had simply used different etching
reagents. In photomicrographs No. 19 and No. 22, Plate IV., the
same specimen was shown, in the first case etched with the reagent
used throughout the present work (FeClg + HCl), and in the second
case with a solution of NH4SO1 and NH4OH. This latter shows up
" the beautiful pale blue colour " of the 8 constituent. He (Mr.
Greenwood) preferred the former reagent, because it was much more
uniform in its action. The 8 constituent etched black whether it
occurred in the massive state or in the network of the eutectoid.
He was interested to have Dr. Andrew's ideas on the question of
cold work in the Brinell test. The test was, however, not capable of
a high degree of accuracy (as applied in the usual type of machine),
and this accuracy became less as the applied pressure was lower.
Hence for soft metals variations in the hardness number, due to
the pressure appUed, were well within the limits of accuracy of the
method. In our present state of knowledge it was therefore unsafe to
push the matter further.
Mr. Haughton had raised the question of the effect of thickness on
the scleroscope test. The specimens mentioned in the paper were
firmly held in the vice whilst the test was being made. There was,
however, one possible difference in the test conditions. Whereas (on
steel) Mr. Haughton had probably used the standard hammer, he (Mr.
Greenwood) had always used the magnifier hammer on the aluminium-
copper alloys. He did not know the susceptibilities of the different
hammers to this particular variation. He had noticed, however
(and so had other people), that much more uniform results were obtained
with scleroscopic measurements on ferrous than on non-ferrous
materials.
He quite agreed that the increase in the transformation temperature
would probably account for the increased decomposition velocity of
the p solutions. He had quite overlooked that view of the question.
He saw the force of all the arguments raised against the choice of
hardness determinations as the best means of attaining the end which
be had in view. He must however call attention to the statement
in the introduction, that this was one of a series of researches which he
hoped ultimately to complete. The scheme was an ambitious one,
122
Author's Reply to Communications
and one which would occupy several years. The author had no facili-
ties for making many of the measurements which he had included in
the scheme, and so it was necessary to use the apparatus at hand, and
hope for better opportunities later. Accordingly he could assure
Dr. Thompson that the electrical conductivity measurements would
be made — but he could not say when.
The remarks which Dr. Thompson had made respecting the hardness
experiments were exceedingly valuable, and had served to crystallize
a number of ideas which had occurred to him whilst preparing the paper.
The curves in Fig. 3 were not extrapolated to zero. It was very difficult
to reproduce the exact end-points on curves of this nature which
rapidly approach one of the axes. The extrapolated portions had
been drawn through points fixed by calculation from the equations
on p. 71, and the zero load values were as follows :
8*7 per cent, aluminium
. H„ = 35
9-7 „
. H„ = 37
10-0 „ „ . . .
. H, = 39
12-6 „ „ . . .
. H„ = 49
13-3 „ „ . . .
. H. = 83
Dr. Thompson developed this matter very neatly, and so derived
from the results a relationship which would otherwise (for the present
at least) have remained dormant. He fully endorsed the reversal of
the meanings which he had apphed to the two factors in the equations
referred to, and would endeavour at an early date to put this develop-
ment to an exhaustive test.
Rix and Whitaker : Die-Casling 123
DIE-CASTING OF ALUMINIUM-BRONZE.*
By H. rix and H. WHITAKER, M.So
Die- CASTINGS may be dej&ned as " finished castings, made by
pouring molten metal, flowing by gravity or under other
external pressure, into a metallic mould."
Advantages of Die-Casting.
Some of the advantages of die-casting are :
1. The accuracy and uniformity of the castings. They can
be made to specification 0*005 per inch, or even less for small
parts.
2. Machining costs are either eliminated altogether or are
greatly reduced.
3. The process is continuous, and the output is generally much
greater than is the case with sand-casting.
4. Articles which it would be impossible to sand-cast may be
successfully die-cast.
Although the process has been in operation for over twenty
years, it is only during the last ten years that it has assumed
importance as a separate industry, and this is largely due to the
development of the automobile and aeroplane.
Metals Employed.
The alloys employed may be divided into five classes, accord-
ing to whether the principal constituent is (1) zinc, (2) tin, (3) lead,
(4) aluminium, (5) copper.
Owing to their low melting points, alloys of the first three
classes were initially employed, but the castings lacked strength
and rigidity. An average zinc base alloy has a tensile strength
of about 8 tons per sq. in., with practically no ductility, but
these alloys are very liable to corrosion and distortion.
The tin- and lead-base alloys include a large number of the
* Read at Annual General Meeting, London, March 14, 1918.
124 Rix and Whitaker : Die- Casting
" Babbitt " or bearing metal type, and many bearings are now
being die-cast.
The low specific gravity, cheapness, and strength (when
alloyed) of aluminium have been the principal factors in its
development as a die-casting metal. The chief drawbacks are :
(1) Its high melting point (compared with lead, tin, and zinc) ;
(2) Its tendency to attack iron when molten ;
(3) Its high shrinkage ;
(4) Its weakness at high temperatures.
On account of (2) the " plunger " type of machine has been largely
superseded by one employing air-pressure, or by utilizing the
pressure of the riser or gate. A die using zinc-base alloys lasts
almost indefinitely, but, when using aluminium alloys, cracks
begin to show after two or three thousand castings have been
made. The high shrinkage of aluminium has been reduced by
alloying and need not exceed about 1*4 per cent.
The weakness of the alloys at high temperatures is responsible
for the formation of cracks which develop while the metal is
solidifying in the mould. Thus the strength of the copper-
aluminium alloy containing, say, 12 per cent, copper drops from
8-10 tons per sq. in. at 0° C. to 3-5 tons at 350° C.
Notwithstanding these drawbacks, aluminium alloys of very
variable composition are being successfully die-cast on a large
scale.
Brass and Bronze Die-Casting.
The next step in the process was to surmount the difficulties
connected with copper-base alloys, which have a much higher
melting point. The literature on the subject is as yet very scanty,
but most of the workers in the field express the opinion that
brass or bronze die-casting is almost a commercial impossibility.
On reading the accounts of the work done by the Doehler Die-
Casting Company,* Work,t Webber,J Schulz,§ Pack,|| and
Norton,** one arrives at the following conclusions :
1. The chief difficulty in the process is the high temperature
(900° to 1000° C.) for casting " yellow metal." This has several
* Doehler Die-Casting Co., Brooklyn, N.Y.
t Mechanical World, October 8, 1915.
j Machineri/, January 19I(j. § Mechanical World, July 21, 1916.
i| Transactions of the American Institute of Metals, 1914 and 1916.
♦* Ibid., (September 1914.
of Aluminium-Bronze 125
effects. The zinc in the brass attacks the steel die, which rapidly
deteriorates, so that no more than 1000 castings can be obtained.
The high shrinkage of brass sets up strains within the die which,
further impair its accuracy. Since the die cost (anything from
£5 to £200) is the prime factor in die-casting, this is a serious
matter. For the same reason it is impracticable to use an iron
container for the molten metal, as the alloy would rapidly become
contaminated thereby ; hence air pressure cannot be employed
to force the metal into the die. This means pouring from the
crucibles, with consequent slowing down of production, if (as is
often necessary on account of expense) only one die can be used.
Another consequence of the high temperature and slow pouring
is the large amount of dross which is formed. Also ordinary
brasses are not sufficiently strong at high temperatures to with-
stand the shrinkage strains which are set up.
2. It is very difficult to produce brass die-castings which are
consistenth'^ free from blowholes or shrink-holes. The former
are caused by air being entrapped in the mould, and they cannot
be overcome by simply increasing the pressure in the mould
or by carrying out the process in vacuo. By a careful study of
the venting and gating of each part, however, this unsoundness
may be practically eliminated.
3. Brass and bronze die-castings are only a commercial success
if the parts cannot be completely produced by automatic
machinery, or when they obviate numerous difficult machining
operations, involving different settings of tools. To compete
with the machined products the die-castings must be rapidly
made, must be accurate to within ±0-002 per in., and must have
a smooth polished surface. Recent developments in foundry
and machine shop practice have made it possible for many parts
to be now more cheaply sand-cast, and " yellow " metal die-
casting is " practically restricted to pieces of fairly simple shape,
weighing between | oz. and 3 lb."
The experiences of the authors in this connection have been
chiefly in the use of brass (60 : 40) containing about 2 per cent,
aluminium ; manganese brass ; and " aluminium-bronze " con-
taining iron. In the first case, the aluminium is added to give
fluidity to the metal and better definition to the castings. In the
second case manganese brass of usual composition is used,
126 Rix and Whitaker : Die- Casting
containing less than 1 per cent, manganese, with a little iron and
aluminium. The chief objection to these metals is that the
surface of the die becomes rapidly covered vntla. a coating of zinc
oxide, which must be brushed off after every cast or the definition
is spoiled. Various methods have been tried to overcome this
difficulty, but so far without complete success.
Our best results, however, have been obtained witli
" aluminium-bronze " containing iron. The first alloys experi-
mented with were of copper-aluminium containing about 10 per
cent, aluminium, the balance being copper. The results were
disappointing, for the metal did not lie so " kindly " to the surface
of the die as it might have done, and the definition of the edges
was poor. After repeated trials it was decided to add a little
iron, when much better results were obtained.
In their masterly research on the copper- aluminium alloys
Carpenter and Edwards * brought the investigation to a point
" where the way is clear for investigating the influence of a third
metal." Eosenhain and Lantsberry,f in their introduction to
the Ninth Eeport, discuss the reasons which led to the selection
of manganese as the third metal, and it is rather singular that
iron does not seem to have been considered as even a possibility.
Vickers J alludes to the prejudice which appears to exist in the
minds of most foundrymen against iron in copper alloys, probably
due to its harmful effect when present in brass in any quantity.
He also states that the use of iron in " aluminium-bronze " is
no new thing, but has been common in Germany and the United
States for some years. While claiming that it improves the metal
for sand-casting, he questions its use in die-casting, for the follow-
ing reasons :
1. In sand-castings it is necessary to add iron in order to
prevent the " excessive crystal growth " which is " such a draw-
back to the 10 per cent, aluminium-bronze."
In die-castings this is not necessary, as the chilling effect of
the die is sufficient to keep down this growth.
(That the iron has this effect is shown by Corse and Comstock.§
Combined probably wdth aluminium and copper the iron is the
* Carpenter and Edwards, " Eighth Report to the Alloys Research Committee," 1907.
t Rosenhain and Lantsberry, "Ninth Report to the Alloys Research Committee," 1910,
± Mechanical World, August 17, 1917.
§ Transactions of the American Institute of Metals, September 1916,
of Aluminium-Bronze 127
first constituent to separate out, in the form of small black
crystallites, which form nuclei round which the a-solution
crystallizes, thus reducing the grain size.)
2. Iron accentuates the shrinkage of the bronze, consequently
increasing the tendency to form the pear-shaped cavities commonly
found in aluminium-bronze die-castings.
The authors do not agree with the above conclusion
limiting the usefulness of copper- aluminium-iron alloys to sand-
castings, having produced many thousand die-castings in these
alloys.
The cavities referred to are certainly a difficulty to be over-
come. They are either shrink-holes, caused by the large con-
traction of the metal, or blowholes caused by air being entrapped
in the die by the molten metal, and they may be detected in a
casting by finding its specific giavity. Their direction is often
radial, and they may be coloured black inside. In either case,
they may be practically eliminated by a careful study of gating,
venting, &c.
Tetmajer * has worked with " aluminium-bronze " containing
iron and silicon, but what appears to be the most complete account
of the copper-aluminium-iron alloys is by Corse and Comstock.f
They have studied the properties of the possible combinations
containing 1 to 4 per cent, iron and 7 to 10 per cent, aluminium
inclusive. Their conclusions are that " for the same aluminium
content there is always an increase of proportional limit, yield
point, and ultimate tensile strength with increasing iron content,
and in general a rather less substantial decrease in elongation
and reduction of area. In the same way, with constant iron
content, the proportional limit, yield point, and ultimate tensile
strength increase with increasing aluminium, while the elongation
and reduction of area decrease. Also, that for a given strength,
better ductility can be obtained with a lower aluminium and
high iron alloy than with higher aluminium and low iron."
It is of course difficult to compare the results of different
workers on similar alloys, owing to lack of uniformity in methods
of preparation and testing, but a comparison of the results con-
tained in the Eighth and Ninth Eeports to the Alloys Research
* Mitteilungen der Material-priilungsanslaU, IX. Heft.
t Transactions~of (he American Institute of Metals, September 1916.
128
Rix and Whitaker
Die-Casting
Committee, and those obtained by Corse and Comstock, leads
to the following conclusions :
1. Iron and manganese, when added respectively to copper-
aluminium alloys (containing 7 to 10 per cent, aluminium), have
a similar effect, i.e. the yield point and ultimate tensile strength
are raised at the expense of the ductility.
2. In the case of sand-cast bars, the addition of iron appears
to give better all-round mechanical properties than the addition
of an equal amount of manganese. The data are not available
for a complete comparison of the chill cast bars, but some
promising results have been obtained by the authors with alloys
containing 7 to 10 per cent, aluminium and 1 to 4 per cent. iron.
The authors are producing die- castings commercially in one of
these aUoys, and the following are the average results recently
obtained from twenty-four test-bars, cast in 1 in. chill and cooled
in air.
It should be pointed out that each bar represents a batch
of castings, produced consecutively during a period of several
months, under ordinarv foundrv conditions.
Diameter of
Test-section.
1 Ultimate
Yield Point. i TensUe
1 Strength,
Elongation on
2 In. per Cent.
Reduction of
Area per Cent.|
1
= 0-564 in.
14-7 tons per sq. in. ; 35-5 tons per
1 sq. in.
24
21-8 j
These results compare favourably with those for the chill
cast bars containing 7 to 10 per cent, aluminium given in the
Eighth Eeport, and for those containing 8 to 10 per cent,
aluminium and 1 to 5 per cent, manganese given in the Ninth
Report. In several cases the latter alloys give better results,
but whether they may be die-cast or not is open to question.
Heat Treatment.
The mechanical properties of the copper-aluminium-iron
alloys may be profoundly modified by heat treatment, and this
probably accounts for the variable results obtained with the
same metal under ordinary casting conditions. Consequently,
Plate v.
Sf,es^ ' 4a^.
Examples of Aluminium Bronze Die-casting Work from Iron Dies.
[To /ace p. 12?I
oj Aluminium-Bronze 129
accurate pyrometric control of the die-casting process is advisable,
if consistent results are required. The temperature of the molten
metal should be known, and that of the die itself, also the rate of
cooling of the hot casting should be standardized. Much different
mechanical properties would result if instead of quenching the
casting red hot from the chill, in cold water, it were allowed to
cool slowly in air.
An advantage of the alloy used by the authors is that it is
sufficiently fluid to fill the die and give satisfactory castings
through a wide range of temperature.
Material for Dies.
The authors have experimented with several materials, ferrous ■
and non-ferrous, for die-making, but have had the best results
with a close-grained cast iron, as hard as is consistent with
good machining properties. The block of iron from which the
die is made is itself chill cast, to give thesie qualities. Sometimes
the dies have been cast almost to shape before machining, but
the results have not been very satisfactory.
It need not be pointed out that a die when once made is only
suitable for one particular alloy. Each alloy has its own require-
ments regarding gating, venting, and shrinkage, and the particular
problems of each new part render it very difficult to make
a correctly designed die at the first attempt. In an iron die as
described above, there can be made from 5000 to 7000 castings
similar to the " Butterfly " type of carbon brush-holder (marked
No. 1) that is shown, along with other examples of c.ie-casting, in
Plate v., before it shows signs of deterioration. No facing or
special treatment of the die surface is necessary, nor is the die
cooled down every few minutes ; but the plugs, which are of
steel, are dipped in a graphite wash between each cast to preserve
their shape ; even then they do not last so long as the die. The
other photographs represent chiefly different types of carbon
brush-holder, all of which are being die-cast on a commercial
scale. The design of the die is a most important factor, and
here it is where experience is the best guide. The design
of the part itself should conform to the special requirements of
die-casting, and thf^'e is need for the closest co-operation between
VOL. XIX. K
130 Rix and Whitaker : Die- Casting
the engineer, metallurgist, and foundry foreman. The number
and shape of the parts of the die, method, and order of with-
drawing the cores, venting, situation, shape and size of the gate,
all must be carefully considered in designing a new die.
Cost of Process.
No general rule can be laid down with regard to costs. In
some cases die-casting is cheaper, in other cases dearer than sand-
casting. The cost of dies, material, labour, and machining must
be gone into before a decision can be come to as to which is the
more economical process. The cost of machining and assembling
of the " Butterfly " type brush-holder above referred to is eight
times as great when sand-cast as it is when die-cast, and the other
parts shown are also cheaper die-cast. The castings are not
sold by weight, as the cost of labour varies both in making the
dies and castings. The die cost is treated as a separate item
from that of the castings, and is generally borne directly by the
customers. *
Die-Casting on a Scientific Basis.
For a scientific investigation into die-casting, the following
might be carefully studied :
The alloy :
(1) Coefficient of expansion at different temperatures.
(•2) Specific heat.
(3) Thermal conductivity.
(4) Mechanical properties at high temperatures.
(5) Mass, volume, and surface area of casting.
(6) Latent heat of fusion.
(7) Metallography.
(8) Pressure on metal in die.
The die-material :
(1) to (5) As above.
(6) Possible attack by molten alloy.
Casting conditions :
(1) Temperature of molten metal.
(2) Temperature of die.
of Aluminmm-Bronze 131
(3) Length of time in die.
(4) Eate and method of cooHng of casting.
Even with all the above information, however, it would still
be necessary, in the case of a new part, to go on more or less
empiric lines before a satisfactory casting could be produced.
It might be feasible to design a standard die which would
serve as a basis for comparison of results obtained by different
observers.
Conclusion.
One of the authors previously quoted summarizes the position
by saying that " the principal secret of die-casting is experience,
which is the result of tireless effort, skill, patience, and — capital."
The thanks of the authors are due to the British Westing-
house Electric and Manufacturing Company, Ltd., for permission
to publish the above paper and the accompanying photographs.
132 Discussion on Rix and Whifaker's Paper
DISCUSSION.
Mr. T. G. Htrst (Leigh) said that he had tried a little die-casting
in alnminium, but the results were negative. lie would be very pleased
to know, in the case of iron, how Mr. Rix and Mr. Whitaker got it taken
up into the copper. At present his firm was using 50 : 50 ferro-copper,
and found on melting that the copper appeared to sweat out of the
alloy and left the iron in a spongy state which did not completely
alloy with the metal, with the result that there were some small black
spots in the finished chill casting.
Mr. F. Johnson, M.Sc. (Birmingham), said that in the year 1916,
in the discussion on a paper given to the British Foundrymen's Associa-
tion on non-ferrous alloys, he drew attention to the importance of
die-casting, particularly in brass, and he pointed that out with emphasis
at the meeting. He had then said that when such alloys became a
commercial proposition there would be a revolution in manufacturing
methods and in costs. He did not go so far as the copper-aluminium
alloys. He was thinking particularly of the copper-zinc alloys, because
of their relative cheapness and because of a die-casting which he had
had presented to him, which was perfect in every detail and which
consisted of brass- — and very ordinary brass at that. It was brass
containing about 64 per cent, of copper, a little tin, a little lead, and
about 03 per cent, or Oi per cent, of aluminium. It struck him
that in addition to the two advantages of using aluminium brasses
which the authors had pointed out, there was the advantage also that
the aluminium present formed an external skin of alumina, and that
external skin lessened the action between the zinc of the brass and the
iron of the mould. He had no further information with regard to
that particular die-casting, as to whether it was produced as a com-
mercial success or not, but it was certainly a very beautiful casting,
and he saw no reason, particularly since the authors had shown that
cast-iron dies could be used, why brass die-castings could not be made
on a commercial scale, i.e. brass containing a small quantity of alu-
minium. He was particularly interested in the authors' reference
to the influence of iron in those alloys, and would £sk them if they
had any experience of copper-iron-aluminium alloys containing a
high percentage of iron — 10 per cent, or even 15 per cent. He thought
there were uses for alloys of that kind, particularly for high tempera-
tures, where they should be more durable than the 'low iron alloys.
They would be perhaps less fusible and less fluid, which reminded
him that the authors had insisted insufficiently on that particular
point of fluidity. On p. 130 the authors did not include it as one
of the propel ties which should be considered when investigating the
Discussion on Rix and Whitaker's Paper 138
properties of die-casting alloys, nor did they insist on the measurement
of the fluid shrinkage as distinct from contraction of the soUd. There
was another point with regard to the influence of iron on the crystal
size which was analogous to the influence of iron on the copper-zinc
alloys. A small quantity of iron in the latter would bring about h,
very great refinement of crystal grain. In the periodical Machinery
some two or three years ago there was some correspondence, which
the authors might have seen, on the difficulties associated with pro-
ducing brass die-castings, and one waiter in the discussion claimed that
the copper -tin alloys had been successfully produced by die-casting.
In view of the paper and the use of cast-iron dies, he would ask the
authors if they had had any experience, or if they would suggest that
there was a possibility of putting copper-tin alloys on the market in
the form of die-castings as commercial articles. He wished to thank
the authors for their paper. He thought it was an extremely welcome
one, and one which had to come in the inevitable course of events.
Mr. P. Peakman (Manchester) said that he had heard a great deal
about die-casting and read a lot about it, but until he went to the
British Westinghouse he had never seen any die-casting made other
than in white metal except on the scrap-heap. When he first went
into the brass foundry there he discovered they were making die-
castings of all shapes and sizes very successfully. With regard to the
shrinkages mentioned by the authors in certain aluminium alloys
when die-cast, from what he had seen those were largely due to the
temperature to which the metal had been subjected in the crucible,
to the temperature at which the metal had been poured, and also to
the temperature of the die when the metal was poured into the die.
In some foundries it had been found that the more rapid stripping
of the die ofi the sohd casting had ehminated those shrinkages, at
any rate to a great extent. The authors had got their results from
top-fed die-castings. That was rather important in connection with
aluminium-alloy work particularly, especially after Mr. Johnson had
mentioned the alumina which formed, or had a tendency to form, on
aluminium alloys, and also prevented the contact of the metal with
the die. If the authors could go further with their work and pour from
bottom-fed dies or side-fed dies, he thought many of the troubles of
poor die-casting would be eliminated. With regard to the aluminium-
bronze die-casting, it would be of very great interest to know whether
it was not possible to put some outside pressure, other than that which
was given, as the authors had pointed out, from the head of metal in
the gate of the die. With regard, to blowholes or air-pockets, which had
been found in many die-castings, he thought those could be reduced
if some care was exercised in the crucible stage, that was, in the
initial periods of making the alloys which were going to be die-cast.
Another point which had cropped up since the authors had given their .
paper was the following. Mr. Whitaker said it was a practical paper,
134 Discussion on Rix and Whitake/s Paper
and at the end, he discovered that there was a list of investigations
which the authors suggested would be of very great value in the die-
casting industry and in solving the problems of die-casting. He would
like to ask, however, how the different pieces of information and data
would be interpreted into foundry language. It had been found up
to the present, at any rate among all die-casters, that without plenty of
capital, without plenty of patience, and without a reasonable amount
of brains, die-casting was an utter failure. So how were the authors
going to interpret the information, when they had it, into the final
die-casting as a commercial proposition ? The best method to his
mind would be to make first of all a standard die, of not too intricate
design, and, after making that standard die, to experiment with
certain metals for die -casting. He knew that meant an enormous
length of time to get all the information through, but the results would
be most valuable. Secondly, after standardizing the die and the
alloy, the best alloy out of the whole series that had been experimented
with should be taken, and the material used in the die manufacture
should be experimented with. There was much room for investigation
into the composition of the actual metal used in the die, and particu-
larly in respect to the various portions of that die. At Westinghouse
a cast-iron die had been foimd to be good and cheap, but the plugs
used were of a different material altogether, and he had been wondering
whether it would not pay even further to put a difierent facing on the
die, to have a facing of some other material, backed up with cast iron,
and then plugs in difierent portions of the die made from various
materials. There was a great deal of work to be done in die-casting,
from whatever point of view it was regarded. The time had arrived,
he thought, when one and all must get out commercial propositions ;
and when Mr. Whitaker told him that his (Mr. Whitaker's) paper
had been accepted by the Institute of Metals he was really delighted
to think that the Institute had opened its doors to such a practical
paper, and one which he was hoping would be heard more about in
connection with die-casting, if not in any other direction.
Professor C. A. Edwards, D.Sc. (Member of Council), said that
he was glad to have an opportunity of saying a few words on the
subject of the paper, especially since he had had an opportunity of
seeing many of the castings made at the British Westinghouse in
Manchester. With regard to the question of dies, he could not help
thinking that the best material to use would ultimately be found to
be something other than cast iron. The one material which he did
hope for in that connection was the very alloy that the British Westing-
house were using to make castings. Its great advantage was that it
had a protective coating of alumina, and that would protect the mould,
he believed, from the action of the liquid metal. All that was wanted
was the correct mass in the die, so that the rate of cooling from the
casting into the die proper would be of the right order. Monel metal
Discussion on Rix and Whitaker's Paper 135
might also give satisfactory results. He had also wondered with the
authors as to what the efiect of iron was. It was a mystery why iron
shoTild have such a markedly beneficial efiect in producing die-castings.
But of course it must be borne in mind that die-casting could be made
in pure copper -aluminium alloys, not so expeditiously, but nevertheless
they could be made fairly satisfactorily. The only explanation he
could give was that the iron was the first to separate from the Hquid,
and thus caused a finer crystalUzation; it probably produced a marked
lowering of the freezing point. His next suggestion was that all those
who took up the question of die-casting should bear in mind one or
two details, one of which he thought had not been referred to by the
authors, and that was : Wherever possible, cast from as low a position
in the mould as could be conveniently arranged. That always pro-
duced a cleaning efiect as regards the alumina on the surface. Then
with regard to melting and how the iron should be added, cast iron
shovJd certainly not be used in making the alloy ; the purest wrought
iron should be used. If cast iron were used to make the alloy, a good
die-casting would never be obtained with it, or at any rate it would not
be commercially profitable. SiUcon was absolutely fatal to the material.
Secondly, the alloy should be melted at as low a temperature as possible,
so that in the melting period siUcon was not taken up from the crucible.
He would hke the authors to consider the following proposition. The
future of die-casting would rest very largely on how much was known
about the treatment of the castings. The authors had selected an
alloy which gave the least trouble, but not necessarily the best results.
That, of course, was quite a proper Une to take in the first place. It
would be useful if alloys containing the a and (3 constituents could
be cast in the same dies. In such alloys, and to a less degree in the
one used by the authors, it was important to know the different mech-
anical properties that would exist in different sections of the casting
because the rate of coohng had an enormous effect in that respect.
It was no use assuming that certain mechanical properties were being
obtained in the casting as a whole ; the properties would depend to a
large extent upon the sectional area of the casting. He saw no reason
why manufacturers,' having no previous knowledge of the subject,
should not be able to make die-castings after a few weeks' experi-
menting, provided they started with fairly simple types and developed
them. He knew of one foundry which twelve months ago knew nothing
about the making of die-casting, but three months later they were
producing thousands.
Dr. W. RosENHAiN, F.R.S. (Member of Council), said that he was
particularly interested in the paper, partly because he had the pleasure
of seeing the operations referred to carried out with really admirable
perfection at the works where the authors had developed their methods,
and also because he had special reasons for taking an interest in die-
casting and in alloys of aluminium-copper. With regard to the value
136 Discussion on Rix and Whitaker's Paper
of die-castings — he was using the word in what was perhaps not the
strict sense, because hitherto he thought most people had understood
by " die-castings " objects produced in chill moulds under definite
high pressure, but he would use the term in the more general sense
defined by the authors — there were certain very definite advantages
attached to die-casting, quite apart from the question of production.
One advantage was that a chill cast alloy was generally a better material
than the same material cast in a sand mould. That was not a vital
matter in articles of the kind under discussion, but it might be a vital
matter in other articles which could economically be produced by
die-casting. With regard to some of the difficulties of the process,
they were, of course, patent to anyone who had ever attempted it or
seen it done. On the question of shrinkage, which was one of the
fundamental difficulties, the authors referred to aluminium alloys,
and they were probably well aware that aluminium alloys at present
were being die-cast in very large quantities indeed. Articles in which
strength and freedom from cracks were of vital necessity were being
produced and put to the most exigent kind of services, having been
cast in chill moulds. In that connection he would say that the
aluminium-copper alloy to which the authors referred, containing
12 per cent, of copper, was one which was not particularly remarkable
for its strength at high temperatures. It was possible to obtain alloys
which were very much stronger at a high temperature than that
referred to in the paper. The risk of cracking during cooling was con-
siderably diminished, but in his opinion the difficulty of shrinkage
was to be got over by stripping the die at the right moment. The
success of the process depended entirely upon so designing and using
the dies that the casting was free from the pressure, and the control
upon its shrinkage, which the internal parts of the die would exert
if not removed at the right moment, neither too soon nor too late.
That was a question partly of experience, but it might be assisted
considerably by an accurate knowledge of the physical properties of
the alloys at high temperatures. Coming to that aspect of the paper
which was particularly emphasized at present, the question of the
action of iron interested him particularly. He was not prepared to
say at the moment what were the reasons by which the Alloys Research
Committee were led, at the time of their Ninth Report, to choose
manganese rather than iron. He thought the consideration which
was present in their minds and in his own mind was that manganese
would have some deoxidizing action, and that, by adding it before the
aluminium, the presence of alumina in the resulting alloy might be
at any rate minimized- It was, he thought, not so much from the
point of view of greatly improving the physical properties, as of
improving the soundness of the castings as well as the general behaviour
of the material that manganese had been tried. What he was about
to remark was a little speculative, because the investigations upon
which he was basing his ideas had not related to the alloys in which
Discussion on Rix and Whitaker's Paper 137
copper preponderated. Unless the presence of copper altered the
relationships entirely, however, he thought there was good reason to
beUeve that iron would be present in these alloys in the form of a
compound, probably FeAlg. That compound had a very high melting
point ; it crystalhzed out from its metallic solutions at a very high
temperature. In the pure state he beheved its freezing point was
somewhere round about 1400° C, but of course that was affected by
the presence of other elements. If there was enough of it, it would
form a sort of skeleton network right through the whole body of the
casting, and materially resist the shrinkage in that condition. He
woiJd further point out that in an alloy containing 7J per cent, of
aluminium and 3 per cent, or 4 per cent, of iron, if it were true, as he
was supposing for the moment without very definite proof, that iron
was present as FeAlg, there might be very little aluminium left in solid
solution in the copper. How much FeAlg itself, or how much iron
could go into solution in the aluminium-copper a body, was not
known. It was a particularly interesting observation when the authors
said that 1 per cent, did not seem to give rise to a fresh constituent.
^Vhat they described, from its shape and its chemical behaviour,
seemed strikingly like FeAlg. He thought it was quite probable that
this compound really existed in these alloys. In that case it ought
to be possible to use higher aluminium contents, which would be very
interesting if it could be done.
The production of the castings under discussion struck him as a
very remarkable achievement, and not only were the authors to be
congratulated upon it, but also upon the policy which had enabled
them to give such an excellent description of the processes and methods
which had led to the present successful result. With reference to one
remark made by Mr. Whitaker, he would only say that if anyone,
even if he were " only an engineer," bought the castings in question
as a brass casting and tried to solder it, he would not bless the name
of the maker.
Mr. J. Dewrance (Member of Council), speaking from the practical
side, said that he had been die-casting for thirty or forty years, and
was a little surprised that cast iron should be so highly spoken of
as the material of which to make the mould. Cast iron being a
porous material, the gases contained in the pores expanded after the
metal was poured into the mould. This was often the cause of great
trouble in die-casting. He had found that nickel or wi'ought metal
was very much better than cast iron where the result had to be free
from blowholes. The life of the chills was also a matter of very serious
importance in considering the cost, because for some reason the cast
iron, after being used for a certain time, changed and became very
peculiarly stressed. The actual point of contraction had, he thought,
been dealt with very clearly. The withdrawing of the internal portion
was sometimes so difficult to accomplish at the exact temperature that
138 Discussion on Rix and Whitakcrs Paper
it had been his experience that the engineering side of the establish-
ment frequently preferred to machine out the internal portion rather
than core it out. If the internal core was not withdrawn at the
exact moment the result was to establish hidden flaws, which were
very troublesome when the work was finished. The actual protection
of the mould was a matter he had studied, and he found that putting
plumbago on with various cements, such as shellac and lacquer, was
very beneficial to prevent the metal from brazing on to the mould.
That of course was not so necessary with more fluid metals, but in
nearly all the metals he had used, even tin alloys, it was necessary
to protect them in some way. If a cast iron chill were taken, and even a
tin alloy poured into it, it would be found that it would not actually
take anything like so good an impression as if it were just coated with
a little lime dabbed on to the chill. In nearly every form of metal
which was used there was some particular facing of the mould which
was proved to be successful, and the reason for it was very interesting
to those who had to deal with chill castings. He appreciated very
highly the paper, because he believed that the future of die-casting,
with the further investigation it would shortly receive, would be very
important to the members of the Institute.
The President said that, before asking Mr. Whitaker to reply
to the discussion, he would like to ask one question and make one
observation. The authors referred to the importance of controlling
the pouring temperature of the particular alloy under discussion, and
he would like to ask exactly how that was done and what form of
pyrometer the authors found most suitable. Secondly, he would like
to confirm what Mr. Whitaker had said about the structure of the
alloys. In what he was going to say he was relying upon photographic
evidence which was sent him some months ago by Messrs. Corse and
Comstock, who he thought were the first to work upon the iron-copper-
aluminium alloys ; at any rate, they were the first to publish results
on the matter. Their photographs showed unmistakably that up
to a certain percentage of iron — he did not remember exactly what
it was ; it varied with the amount of aluminium — that element was
dissolved in the a solution. Above that the iron was deposited in
the form of well-defined crystals within the a areas. One of the
results of the addition of the iron was a very considerable diminution
in the size of the crystals. He would therefore like to confirm what
Mr. Whitaker had said on this point. Exactly why that should give
the good finish to the alloys was, however, not obvious.
Mr. Whitakeb, replying to the discussion, informed Mr. Hirst
that the iron was put in as a copper-aluminium-iron alloy containing
60 per cent, copper and about 20 per cent, each aluminium and iron ;
it might without detriment, however, be put in direct.
With regard to Mr. Johnson's remark about the die-casting of
Author's Reply to Discussion 139
brass containing a little aluminium, he and his colleague had used
such an alloy, but had given it up in favour of aluminium-bronze for
the reason already indicated, that the zinc attacked the die and coated
it with oxide, producing a bad surface on the casting.
With regard to copper-aluminium alloys containing such large
amounts as 10 to 15 per cent, of iron, he would quote Messrs. Corse
and Comstock's conclusion that it was useless to add more than about
6 per cent. Beyond that percentage there might be a shght increase
in ultimate strength and yield point, but the ductility would decrease
to a low value. These investigators had found, for example, that the
alloy containing 10 per cent, aluminium and 8 per cent, of iron had an
elongation of 11 per cent, and a reduction in area of 12 per cent. This
was rather too brittle for most purposes. The authors had had a
little experience of copper-tin alloys in connection with die-casting,
but had not been able to produce so good a surface as with aluminium-
bronze.
In answer to Professor Edwards (and Mr. Peakman) : quite a number
of the castings at present being made were bottom-fed (an example
was exhibited) with the object of obtaining a better surface. The
only objection to this procedure was that the bulk of gates, risers,
&c., was increased, and sometimes therefore it was more economical
to cast with a rougher surface and then machine a little.
With further reference to the subject of standard dies, Mr. Rix
and he, when trying a new alloy, always used the die for the " Butter-
fly " type carbon brush-holder (marked No. 1 in Plate V.). They
found that if the alloy would make a satisfactory casting in this die,
then the castings in the other dies would also be satisfactory. He
believed it would be possible to design a standard die in which a casting
could be produced having, for example, such differences in sectional
area that a good idea could be obtained from it as to the feasibility of
die-casting any new intricate part.
Mr. Parker (referring to the " Butterfly " die mentioned above)
asked if the metal flowed straight in against the centre plug.
Mr. Whitaker repUed in the affirmative.
Mr. Parker asked if it was found that the plug got worn away
by the continuous flow of the metal, time after time.
Mr, Whitaker replied that was so ; as a matter of fact the plugs
(which were of chrome-tungsten steel) received much more severe
treatment than the rest of the die, for example when being withdrawn,
and consequently had to be renewed two or three times during the
life of the die.
With reference to Professor Edwards' remarks on die-material,
the authors had not tried a die made of aluminium-bronze, but would
endeavour to do so and would communicate the result later.
140 Authors* Reply to Discussion
The iron introduced into the alloy was wrought iron, not cast ;
it was in the form of horseshoe nail clippings, quite small thin pieces
of pure wrought iron which were rapidly taken up by the alloy.
Professor Edwards had raised an interesting point with regard to
the variation in strength in different parts of a casting, corresponding
to difEerences in sectional area ; this was of great importance in con-
nection with test-bars and specifications for die-castings. For example,
the 1-inch diameter chill bar, air-cooled, gave 15 tons " yield," 3-5 tons
" ultimate," and 24 per cent, elongation, while the |-inch diameter
bar gave over 20 tons " yield," over 50 tons " ultimate," and practically
no elongation. It was. of course, essential to know the strength of the
casting itself, and not of the test -bar.
In reply to Dr. Eosenhain, with regard to the title of the paper, the
authors preferred the term " die-casting " to " chill-casting," taking
into account the fact that the metallic mould used was generally
referred to as the " die," the term " chill " being used for the solid
blocks of metal used in moulds to produce local hardness. Moreover,
there did not seem any difierence in principle between forcing molten
metal into a die under, say, 200 or 300 lb. pressure per square inch
and in pouring it in under its own weight.
Dr. Rosenhain's remarks regarding the form in which the iron
existed in the alloy were very interesting. The high melting point
of the compound FeAla indicated that this would be the first con-
stituent to crystalUze out, thus confirming the views of Messrs. Corse
and Comstock. Aluminium bronze could be soldered by galvanizing
it first, or by copper plating.
Replying to Mr. D3wrance regarding facing materials for dies
when using copper-zinc alloys, the authors had tried graphite, French
chalk, kieselguhr, and many varieties of oil, but had not found anything
quite satisfactory.
With reference to the President's question as to the type of pyro-
meter used to control the pouring temperature, the authors did not
use any pyrometer in the ordinary foundry practice ; nevertheless
they were convinced that only by so doing could quite consistent
results be obtained.
The President said the very interesting discussion that had
taken place upon the paper was an indication of its excellence and its
suitabihty for discussion. He was sorry to have " caught out " the
authors by hLs question ; he had no intention of doing that. H) did
not realize that that was the position. /
Mr. Whitaker said Mr. Rix and he used base metal couple pyro-
meters when pouring the fight aluminium alloys, but these would
not stand up to the more severe conditions of pouring aluminium-
bronze. They had, say, twelve men each operating independently
at different dies, and to equip each of them with an expensive platinum
Communications on Rix and Whitaker's Paper Ul
pyrometer, requiring constant care and attention, was not at present
a commercial proposition.
The President said lie was wondering whether an optical or a
radiation pyrometer would be found satisfactory.
Mr. Whitaker said they were hoping shortly to obtain a pyrometer
of the radiation type which could be used in the brass foundry.
COMMUNICATIONS.
Mr. H. Whitaker (Manchester), in further reply to the discussion
at the meeting, wrote that the commercial aspect of die-casting should
not be overlooked. Die-casting was at present competing with sand-
casting for certain classes of non-ferrous work, and the question which
had to be settled in any particular case was, broadly speaking, whether
the cost of the die-casting (involving possibly an expensive die) was
greater or less than the cost of the corresponding sand-casting plu.: the
cost of the extra machining necessary. It could not be too strongly
emphasized that each case had to be considered on its merits, so that
although a thorough knowledge of the alloys employed (as indicated on
p. 130) would be of great assistance to the practical man, the economic
factors often outweighed the purely metallurgical factors.
As pointed out by Professor Edwards, Mr. Kix and he had chosen
an alloy which gave them least trouble when working under ordinary
foundry conditions, i.e. as it contained 7-8 per cent, aluminium, the /8
constituent was entirely absent, and consequently the variations in
strength due to differences in heat treatment were not so great as if it
had been present.
The discussion on Professor Carpenter and Miss Elam's paper,
" An Investigation on Unsound Castings of Admiralty Bronze," had
further emphasized the fact that non-ferrous metallurgists were still
waiting for a pyrometer which should be cheap, accurate, and robust
enough to stand up to foundry conditions. Until such an instru-
ment was forthcoming, however, it would seem a difficult matter to
obtain uniform results with copper- aluminium alloys having a duplex
structure.
Dr. Eosenhain's remarks as to the function of the iron in the alloy
were interesting, and appeared to explain the reason for obtaining a
better sm-face t^an with the alloy containing no iron. By separating
out first, as FeAlg, the iron would cause a considerable reduction in
grain size, both on the surface of the casting and underneath, thus
causing a smoother surface ; it would also " hold " the shrinkage, and
sharper defibnition would be obtained. Chilling in itself would reduce
142 Communications on Rix and Whitaker's Paper
the grain size, and the presence of iron in the alloy would accentuate
this. There seemed to be room for useful investigational work on the
subject of grain size in connection with the surface appearance and
other properties of die-castings. In fact, there were any number of
problems in die-casting which were awaiting investigation on a scientific
basis, and it was with the object of arousing interest in the subject
that Mr. Rix and he had presented their paper. They were very
pleased with the cordial reception it had received from the members of
the Institute, and hoped at some future date to give an accoimt of
further work on the subject.
Mr. J. E. Hurst (London) wrote that he was very deeply interested
in the remarks made by the authors concerning the excellent service
given by cast iron as the die material.
It was very significant that cast iron should be so universally
approved both for use as chills as well as dies throughout all foundry
practice. Generally speaking, so far as his own knowledge went, cast
iron appeared to give the most satisfactory results in this connection
irrespective of what metal was being cast. The reason for this was
decidedly obscure, and it would be interesting to know to what property
of cast iron these successful results were ascribed by the authors.
In their own case it was doubly significant when it was remembered
that the die material at least in parts would have to withstand a
temperature of 900° to 1000° C, or even more.
He would be very interested to know the amount of phosphorus
present in the iron used, also it would be useful to know whether
the authors had encoimtered a peculiar trouble which was decidedly
real in the case of chills used in connection with iron foimding. He
had in mind the so-called " blowing " experienced with chills which
had been in use for some time.
He would further be interested to know whether they experienced
any distortion in dies made from cast iron after prolonged use. In a
recent paper of his own on " Grey Cast Iron," * he there indicated the
possibility of the production of a more or less " steely " case on the
surface of cast iron which might be of considerable value in the produc-
tion of cast iron dies. Owing to lack of time, the conditions under
which this case was produced had not been fully investigated, nor had
its effect on prolonging the life of cast iron dies, although this was under
investigation.
If the authors considered this suggestion of any value, he would
be pleased to give them further details — details which were too long
to be dealt with here.
In conclusion, he would like to congratulate the authors on their
achievements which, without the slightest doubt, marked a distinct
advance in the science of metallurgy.
* Proceedings of the Slaffordshire Iron and Steel Institute, December 1917.
Authors' Reply to Communications 143
Mr. H. Rix (Manchester), replying to the written discussion, wrote
that he had read Mr. J. E. Hurst's communication with great interest.
So far as his (Mr, Rix's) experience had gone, cast iron was un-
doubtedly the best material for dies, and he thought that possibly
the advocates of steel, wrought iron, and the other materials had not
experimented sufficiently with cast iron to obtain it in its most suit-
able form for dies. The question of cost must always be borne in
mind, and while admitting the possibility of obtaining a material
which would not be attacked so quickly as cast iron, he did not think
there was much wrong with a material in a die of which seven or eight
thousand castings could be made, which was so readily and cheaply
obtainable, and so easily machined.
With regard to the reason for the success of cast iron in this capacity,
he could not offer a strictly scientific explanation, but would suggest
the following. In the first place, the block of iron from which the
die was made was itself cast in a die or chill, thus producing sudden
cooling and reducing the size of the graphite particles, and a close-
grained structure was the result. He thought that the innumerable
particles of graphite on the surface of the die would act almost as a
graphite facing and protect the iron from the action of the molten metal.
Secondly, the presence of a considerable amount of this soft graphite
disseminated through the bulk of the die would take up the expansion
and contraction of the more rigid iron grains, thus preventing distor-
tion. One would expect a more elastic behaviour from cast iron
than from, say, steel (in which the crystals are packed tightly together
without any intervening graphite), consequently in the latter case one
would be likely to get internal strains and distortion.
With regard to the amount of phosphorus in the iron used, he had
not had the time to go into this point fuJly, but would quote the follow-
ing analysis (taken from a die at random) which might be regarded as
fairly typical :
Combined Carbon. Graphite. Silicon. Manganese. Sulphur. Phosphorus,
0135 3-35 2-40 0-43 0-10 1-3
The phosphorus content was certainly high, and he thought this
to be advantageous ; at any rate not detrimental. W. J. May, writing
on " Permanent Iron Moulds for Castings," * stated that moulds should
be made of soft iron, fairly high in silicon and graphite and low in
combined carbon. He quoted the following analysis as typical of
suitable material :
Combined Carbon. Graphite. Silicon. Manganese. Sulphur. Phosphorus.
0-84 2-76 2 02 0-29 007 0-89
High phosphorus he regarded as necessary to give fluidity to the metal
and to obtain sharper moulds (when these were cast, not machined),
but high combined carbon would cause growth and deformation.
♦ Mechanical World, Aug. 20, 1915.
144 Authors' Reply to Communications
He (Mr. Rix) had been very interested to read Mr. Hurst's papers *
on the effect of heat on grey cast iron, and noted that he (Mr. Hurst)
attributed the cracking of Diesel engine pistons to a high phosphorus
content. He (Mr. Rix) did not think the point had been conclusively
settled, but would be glad to hear further from Mr. Hurst on this
subject. He (Mr. Eix) had not had much experience of the trouble
known as blowing, nor was the distortion trouble very pronounced
in cast iron dies ; the chief trouble was the cracking of the dies after
being in use for some time, small cracks developing generally at right
angles to the main axis of the casting. This was most pronounced,
natiually, in the region of a thick section of the casting (where much
heat was given up). When the casting was of uniformly thin section,
so that the heat from the molten metal was quickly disseminated, the
life of the die was greatly increased.
Mr. Hiu'st's remarks regarding the formation of a steely case
on the surface of the die seemed to indicate that this would be a valuable
method of protection, and he (Mr. Rix) would be glad to collaborate
with him in its further development. He would like again to thank
Mr. Hurst and other members for their kind reception of the paper
presented by himself and Mr. Whitaker.
* "Grey Cast Iron," Staffs. Iron and Steel Institute, Dec. 1917. "Notes on the Heat
Treatment of Grey Cast Iron," Journal of the Iron and Steel Institute, No. II., 1917, p. 121.
Gulliver : Note on Grain Size 145
NOTE
ON GRAIN SIZE.*
By G. H. GULLIVER, D.Sc, F.R.S.E.
In studying tlie features of a piece of metal or alloy it ia of interest
to measure the dimensions of tlie crystalline units, and to seek relations
between the physical properties of the mass and the size of the crystals.
Sometimes those dimensions are so variable that any effect of their
magnitude is obscured by other factors, but there is a fairly wide-
spread belief that, under favourable conditions, the crystal grains
approximate to a uniform size and uniform compact shape through-
out the piece, and the term " grain size " is in common use. It ia
unfortunate that there is frequently insufficient evidence that the
employment of this term is legitimate.
The term " grain size " is usually applied to the average area
of section of a crystal grain, found by dividing the number of sections
visible on a given micrographic area into the magnitude of the area ;
and the use of the term is often considered justified if the examination
of several micrographs, taken at different positions and directions in
the piece, yield nearly the same numerical value of the mean granular
area. A cursory examination of a micrograph shows that there is a
large variation in the size of the grain sections — too large, in fact,
for the satisfactory employment of a mean if the sections were dia-
connected quantities. Actually, of course, the areas of the various
grain sections do not vary independently ; the real significance of
" grain size " is mean granular volume, and the term implies that
the volume of each crystal grain approximates with sufficient near-
ness to the average volume to allow the term to have a real meaning.
The size of a grain is measured as a two-dimensional quantity,
because the determination of a granular area is much easier than
that of a granular volume, and, for the same amount of trouble, it
gives a more reliable indication of size than a linear measurement
would do. If all the grains in a mass are of nearly the same size and
shape, it does not much matter, apart from the question of convenience,
whether the size is measured as a one-, two-, or three-dimensional
quantity, since the three quantities bear nearly fixed relations each
to the others ; but variation in the size of the grains, in their shape,
or in their manner of distribution, disturbs those dimensional relations.
Attention is confined here to the relation between the mean volume
* Preaent«d at Annual Qsneral Mwting, London, Match 14, 1918.
VOL. XIX. L
i4G Gulliver : Note on Grain Size
of a grain and its mean area of section, when the material shows only
one kind of structural constituent. If the grains are distributed in
random manner throughout the mass, their polygonal sections on the
prepared surface are of variable magnitude. But with grains of
approximately equal volume, and approximately the same compact
shape, a micrograph of given area, large compared with the maximum
area of section of a grain, shows a nearly constant number of grain
sections, from whatever part of the mass it is obtained. Reasonable
objection may be made that the wording of the last sentence is too
vague, and that some more definite language should be used. Accord-
ingly, " approximately equal volume " may be interpreted as indicating
a permissible variation in volume of, say, ± 10 per cent. ; " approxi-
mately the same compact shape " may be regarded as meaning a
polyhedron of, say, 12 ^ | faces, with a permissible variation of
i 5 per cent, among its corresponding diameters ; and " large " may
be taken to mean that the measured area of the micrograph includes
not less than 200 grain sections. These figures are chosen arbitrarily,
but it "is believed reasonably. Before the manner of distribution can
be determined, it is necessary to discover a few specimens in which
the grains are of reasonably uniform size ; so far, no such specimens
have been found, and the effect of distribution must be left out of
account for the present.
The approximate relation of the two-dimensional grain size to the
mean granular volume can be determined in the following manner.
Suppose the mass of material to be a cylinder of any form of section.
Let the height of the cylinder be H, and let its cross-sectional area
be A.
Let N be the total number of grains in the cylinder. Let the
mean diameter of a particular grain be d. Then the mean volume of
that grain is hd}, where h is a numerical fraction which depends upon
the shape of the grain.
Let d be the average value of d for the N grains. Then, if the
variation among the grains is limited, as stated above, the average
granular volume is equal to h {dy, with an error of not more than + 4
per cent.
Let a number of parallel slices of the cylinder be taken at small
distances h apart, and let n be the mean number of grains cut by one
face of each slice. Then the total number of grain sections made by
one face of all the slices is
■px
n . (number of slices) = n . .
h
The total number of grain sections is also
N . (number of sections of each grain) — N
Therefore
H ^T d
n. _ = N . -
Gulliver : Note on Grain Size 147
And
^ ^ J. d^ ^ AH "(i _ A
Or the mean area of a grain section, ^\^thin tlie limits of error
already stated, is
t = *(^)'-
The diameter which is to be regarded as the mean diameter d
of a grain is that which will yield an average number of sections of
the grain ; it may be taken as the arithmetic mean of the diameters
of two spheres approximating, as closely as the shape of the poly-
hedron will allow, to an inscribed and a circumscribed sphere.
The value of Jc for a polyhedron of compact form, having an average
of 12 faces, is somewhat less than |, say, 0-48 ^ 5 per cent. Thus
the approximate area of a grain section is
A ^ (7)2
TJ 2
And the mean volume of a grain is, in round figures,
A
where — is the area usually denoted grain size.
From the above result may be obtained another which promises
to be of greater interest, though the degree of numerical accuracy is
less than before. -It has been stated that, if the grains are approxi-
mately equal and equiaxed, a section of the mass taken at random
yields a nearly constant grain size. But the converse is not necessarily
true, and a constant two-dimensional grain size might only indicate
a recurrent form of distribution as, for instance, one in which a large
grain is surrounded by several smaller grains. A ready means of
detecting a gross departure from uniformity is to measure the areas
of the grains on a suitable micrograph, and compare the maximum
with the mean.
The area of the largest section which can be cut from a grain is
cd*, where c is a numerical fraction approximating to 0*8 when the
section is a polygon of compact shape with 6 to 10 sides, and d has
the meaning already assigned to it. Taking the limits of variation in
the grains as before, and ignoring for the moment any variation in
the coefficient c, the extreme limits of variation of the maximum area
are about ± 12 per cent.
The value of the ratio of maximum to mean grain area, as actually
measured, will vary on account of
(1) Variation in the size of the grains,
148 Gulliver : Note on Grain Size
(2) Variation in the shape of the grains,
(3) Improbability of any one grain being cut exactly along a plane
of maximum area.
The ratio will be increased on account of (1), and decreased on
account of (3). With regard to (2), the value of c changes, but not
greatly, with the number of sides of the polygon. The maximum
variation of the ratio is in the neighbourhood of 20 per cent., and the
value of the ratio is
tnaxiinain grain area 08 . _ . „„
-. =7TXo = 1"7 ± 20 per cent.
mean grain area 0-48 -^ '^
or, roughly, from 1| to 2. An alteration of the arbitrarily chosen limits
of variation among the grains will of course alter the limits of accuracy
of the numerical result.
The above ratio, though its possible values lie between somewhat
wide limits, may be usefully employed as a criterion of uniformity of
the grains ; that is to say, if in a section of a metal, with approximately
equiaxed grains, the ratio of the largest grain area to the mean grain
area is sensibly greater than 2, the grains cannot be described as of
nearly uniform size. Geometrical distributions of grains are possible
from which special sections would give a value of the criterion lying any-
where between 1 and 2, or even considerably above 2, but such distribu-
tions are not regarded here. A criterion less than about 1| would
indicate a special kind of distribution.
The obvious sequel to the preceding paragraphs is an extensive
series of actual measurements. At present little time is available
for matters of interest not directly connected with the war, and the
specimens measured have been neither numerous nor entirely suitable.
The value of the ratio of maximum to mean grain area in these was
found to lie between 3| and 5, the higher values being obtained after
longer periods of annealing ; in other words, the grain size was far
from uniform, and annealing increased the degree of non-uniformity.
There is a temptation to say more about the change in the size of the
grains during annealing, but the matter will not be carried further at
present, or the length of a '" note " will be too much exceeded.
The above arguments may be extended, with slight modification,
to certain alloys which show more than one structiiral constituent.
In a case where the crystal grains, although of approximately uniform
shape and volume, are not of compact form, the use of the term " grain
size " is not convenient without proper reference to the shape of the
grains ; examples are the elongated prisms of a drawn bar and the
pyramids of a chilled casting. The dimensional relations in such a
case are obviously different from those given here, and they are not
the same for all sections of the mass.
Discussion on Gulliver's Note 149
DISCUSSION.
Dr. W. RosENHAiN, F.R.S. (Member of Council), wished to say
one word to welcome the Note. It was, he believed, the first time
the Institute had the pleasme of having Dr. GuUiver present in person.
The papers which the Institute had from him before were somewhat
of an esoteric character and difficult to discuss. The present Note
represented the consideration of a very important question, but one
which again did not lend itself to verbal discussion.
The President said that if no member desired to contribute to
the discussion of the Note, perhaps he might also say that the author
had previously laid the Institute under a great obhgation by his book
on Metallography. Nearly all of the works on metallography which
had been published hitherto had been written by chemists or physical
chemists, but Dr. GuUiver, as an engineer, had written his took from
a difierent standpoint, and that had given ib its distinctive character,
and had made it specially useful in certain respects. He would Hke
to emphasize that point and assure the author, though his Note had
not proved suitable for discussion, it was none the less welcome.
Ellis : Note on Lead-Tin- Antimony Alloys 151
NOTE
ON LEAD-TIN-ANTIMONY ALLOYS.*
By 0. W. ELLIS, M.Sc.
The investigation now described had for its aim tlie determination of
the appHcabiUty of certain of the cheaper ternary alloys of lead, tin,
and antimony in the manufacture of small fittings subsequently to be
submitted to tensile stresses varying in amoimt up to 10 tons per sq.
in. While the results of the trials have proved of little value in'the
connection for which they were instituted, they may yet serve a useful
purpose, particularly as certain of these alloys are now being utilized
in the manufacture of die-castings. They are, for this reason, pubhshed.
Though the primary object of the research was the determination of
the tensile strength of these alloys, Brinell hardness tests and tests in
compression have also been made and are here included.
The strengths in compression of a few of the alloys of lead, tin, and
antimony have been determined by Charpy, whose tests were made
on prisms of the alloys in question, each prism being 15 mm. in height
and of 10 mm. square section. Only one of the alloys examined by
Charpy falls within that portion of the system examined by the author.
The full list of Charpy's tests is, however, given below :
Load Correspond-
Load Correspond-
Lead.
Tin.
Antimony.
ing to a Compres-
ing to a Compres-
Per Cent.
sion of 0-02 Mm.
sion of 7 '5 Mm.
Kilos.
Per Cent.
Per Cent.
Kilos.
80
10
10
800
1775
60
20
20
1050
1700
40
40
20
1150
1825
20
60
20
1350
2200
10
80
10
1100
2700
The constitution of this system has been considered by Loebe,t
and by Campbell and Elder. | The constitution diagramjhas been
shown by these observers to be divisible into four areas, portions only
* Presented at Annual General Meeting, London, March 14, 1918.
t Metallurgie, 1911, 8, pp. 7-16, 33-49.
t School of Mines Quarterly. 1911, 32, pp. 244-255.
152 Ellis : Note on Lead-Tin- Antimony Alloys
of tliree of wliicli liave been dealt with by the author. That section of
the constitution diagram with which this note is concerned is shown in
Fig. 1. The alloys that have been examined by the author are, for
convenience, indicated in the diagram by circles, against which are
affixed the numbers by which these alloys are designated below.
All the members of the series, with the exception of No. 20, were chemi-
i5 ^ ANTIMONY.
i5 %■
Fig. 1.
tally analyzed subsequent to test, in order that due allowance should
be niade for possible errors in mixing or in manufacture.
The alloys were made from high-grade metals of commercial quality.
The lead and tin contained only traces of impurities ; the antimony
was not analyzed, but a full analysis of one of the test-pieces failed to
reveal more than traces of elements other than the three components of
these alloys. The alloys were made up to 400 grms. in weight, and
subsequent to melting were cast at as low a temperature as possible
consistent with efficient pouring ; not more than traces of dross were
observable on the " melts " prior to pouring. The alloys were cast in
chill moulds f in. in diameter. The cast rods obtained approximated
closely in general dimensions to the small fittings already referred to.
Ellis : Note on Lead-Tin- Antimony Alloys 163
No.
Lead (by difierence).
Tin.
Antimony.
1
880
41
7-9
2
86-5
8-6
4-9
3
81-8
131
5-1 i
4
76-8
14-8
8-4
5
72-6
221
5-3 '
6
65-7
28-7
6-6
7
86-2
4-6
10-2
8
82-0
8-9
91
»
75-1
14-7
10-2
10
71-0
18-6
10-4
11
66-8
230
10-2
12
79-6
4-5
15-9
13
77-1
8-6
14-3
14
66-4
190
14-6
15
66-0
18-9
151
16
701
4-6
25-3
17
68-8
91
221
18
641
13-9
220
19
72-2
4-6
23-3
20*
65-0
100
250
21
64-2
5-9
29-9
From the cast rods sections for the manufacture of tensile test-pieces
were cut. Three of these test-pieces were fractured in tui-ning — Nos.
13, 16, and 20 — though the machining of the test-pieces as a whole
was conducted with apparently equal care and skill in all cases. The
residues of the rods were retained for manufacture into com-
pression and hardness test-pieces. Unfortimately certain of the
compression test-pieces were mislaid, and time has not permitted of
the production of other test-pieces of the same composition.
The tensile test-pieces were 0-326 in. in diameter and 1*155 in.
between the gauge marks, the latter distance being four times the square
root of the cross-sectional area of the test-piece. The compression tests
were made on test-pieces having a sectional area of 0*25 sq. in. and
having a length equal to twice the diameter of the samples.
The following table (p. 151) includes the results of all the tests
made on the alloys in question.
The results contained in the following table are considered sufficient
to merit the following conclusions : (1) that the efEect of the presence
of the tin-antimony compound in these alloys is such as to render the
same brittle and weak ; (2) that the general mechanical properties
of the lead-tin-antimony alloys containing less than about 15 per
cent, of tin are improved by the addition of antimony in quantities
not exceeding about 10 per cent. The lines A B and tin 15 per cent,
in Fig. 1 appear to enclose the alloys possessed of the most satis-
factory mechanical properties in a general sense ; and (3) that, as far
as that part of the diagram shown in Fig. 1 is concerned, the efiect
of increasing the content of antimony in any alloy is to lead to an
♦ Not analysed.
154 Ellis : Note on Lead-Tin- Antimony Alloys
increase in the hardness of the same. There appears, however, to be
a region of maximum hardness in the vicinity of the 70 : 10 : 20 alloy.
(
No.
Yield Point.
Tons per
Sq. Inch.
Tenacity.
Tons per
Sq. Inch.
Elongation
per Cent.
Compression
Load in Tons
required to
Compress to
Half Length.
Brinell \
Hardness j
Number. 1
10 Mm. BaU,
200 KiloB.
1
1
214
2-41
1-5
12-7
15-2
2
214
3-22
30
N.O.
161
3
2-68
3-35
20
N.O.
16-7
4
2-81
308
10
N.O.
18-0
6
N.O.
2-41
...
8-9
16-8
6
2-96
3-75
1-5
N.O.
161
7
i-01
617
10-5
12-6
23-2
8
3-86
6-43
130
11-0
26-4
9
3-75
6-43
5-5
N.O.
26-4
10
401
509
1-5
90 C.
23-2
11
3-76
6-36
10
N.O.
240
12
308
5-22
4-0
N.O.
25-6
1 13
Broken in machining
11-6
310
14
3-48 ' 6-36 1
10-7 S.C.
320
15
3-48 5-36 1 1-5
9-7 S.C.
27-6
16
Broken in machinius
12-6 S.C.
26-6
17
4-55
' 4-65
9-8 ♦
370 1
18
4-28
5-09
100*
35-6 1
19
3-48
3-48
8-8*
27-8 j
20
Broken in machinins
8-3 *
33-6
i "
3-75
5-62
1-0
6-5*
28-8
N.O. — ^Not observed.
C. — Cracks in compression test-piece.
S.C. — Slight cracks in compression test- piece.
* — Failed without compression to half length.
Carpenter and Elam : Unsound Castings 165
AN INVESTIGATION ON UNSOUND CASTINGS
OF ADMIRALTY BRONZE (88 : 10 : 2) : ITS
CAUSE AND THE REMEDY.*
By Peofessor H. C. H. GARPENTEK. M.A., Ph.D., AJR.S.M. (Peesident)
AND
Miss 0. F. ELAM.
In a recent publication of the American Bureau of Standards,*}"
entitled " Standard Test Specimens of Zinc Bronze," dealing
entirely with a bronze of the composition 88 per cent, copper,
10 per cent, tin, and 2 per cent, zinc, the authors, Karr and
Kawdon, have attempted a complete investigation of the
mechanical properties of this alloy, as influenced by the methods
of casting and heat treatment, so as to arrive at a standard
method for its manufacture. They have come to the conclusion
that the casting temperature has the greatest effect on the qualities
of the material. This applies to all forms of castings, whether
sand or chill. The temperature affects the rate of cooling and
therefore the crystalline structure, the presence or absence of
blowholes and of oxide pits and films. From the results of
many experiments, and from a comparison of the properties
of the test-pieces, they decided that the best results could be
obtained by pouring within a certain range of temperature,
viz. between 1120° and 1270° C. The actual temperatures
were taken immediately before pouring by means of a platinum-
platinum-iridium thermocouple.
Besides the blowholes and oxide pits they consider the most
serious defect to be oxide films, which frequently follow the
" eutectic," in itself a brittle constituent, and a source of weakness
if not properly distributed. These films are probably tin oxide,
and are often associated with pits filled with the same substance.
* Read at Aaaual Geaeral Meeting, Loudon, March 14, 1918.
t Technologic Paper* of the Bureau of Standards, No. 69 : " Standard Test Specimani of
Zioo Bronze."
156 Carpenter and Elam : An Investigation on
Heyn and Bauer,* in a paper on oxygen in copper-tin alloys,
state that tin oxide (SnOo) is insoluble in molten copper, and
is either present in the solid as crystals or forms these films.
Rawdon, dealing with the microstructure of Admiralty bronze,
bears out this statement.
H. S. Primrose, f in " Metallography as an Aid to the Brass
Founder," mentions two pouring temperatures only, 1100° C.
and 950° C, the latter probably an error in printing, as Admiralty
bronze solidifies at about 985° C. In his opinion blowholes
may be due to steam from the mould, occluded gases from the
metal, or .included oxides. The latter can only be removed
by remelting with phosphor-tin or phosphor-copper. In metal
poured at too low a temperature " intercrystalline pores " are
formed by the quick uniform contraction of the casting.
None of these investigations, however, deals Ydth the character-
istics of the various types of unsound alloys that are liable to
be produced when \sTong pouring temperatures are adopted.
This is somewhat remarkable, inasmuch as the different appear-
ances of crystallization are very striking. Neither do any of
them give any information as to the gases in the fluid alloy whose
separation and partial evolution during freezing are responsible
for the unsoundness. So far as the authors have been able to
ascertain the literature contains no analyses of these gases, and
in the absence of this knowledge attempts either to get rid of
them, or, better still, to prevent their presence in the alloy, must
be pui'ely empirical. A prevalent idea is that oxygen gas plays
a considerable part in causing the unsoundness.
Understanding that, in spite of the existence of the publica-
tions alluded to, difficulties still exist in the foundries in this
country in casting sound Admiralty bronze (88 : 10 : 2) the
authors decided to undertake an investigation whose object
should be, in the first place, to obtain fuller information on the
exact cause or causes of unsoundness, and in the second place —
assuming success in the first stage — to devise a suitable remedy.
In coming to this decision they derived much benefit from con-
versations with Mr. J. DeAVTance, himself the originator of this
particular alloy, whose experience of its properties is very con-
* Zeitschrifl fiir aiiorganische Cheinie, 45.
t Journal of the IntliltUe of MetaU, 1910, vol. ir. p. 248.
Unsound Castings of Admiralty Bronze 157
siderable. Further, he has kindly given them every facihty in
his foundry for carrying out their experiments, and his help has
been of the utmost value and assistance.
From experiments carried out in the foundry alluded to, it
was found that there are two distinct varieties of unsoundness :
(1) When the metal was poured too hot, in which case the metal
actually rises in the mould, and which is due to the formation
of blowholes ; (2) when poured too cold and the surface sinks.
Between the two extremes there is a temperature range in which
sound castings are obtained, the surfaces of which are fiat. When
poured too hot the metal is always unsound. The lower limit
of unsoundness is not so well fixed, the castings generally showing
holes, but not always.
About 50 lb. of copper were melted in a gas or coke furnace.
When molten the zinc was added and the temperature raised.
The tin was added last after the pot was removed from the furnace.
The total time the pot was in the furnace was on an average
forty-five minutes. The first cast was made as soon as possible,
while the metal was at its hottest. It was poured into sand in
rectangular blocks 3f in. X 3f in. X 6 in. in size. Both wet
and dry sand moulds were used with the same results. The
temperature was taken in the crucible by means of a platinum-
platinum-rhodium thermocouple protected by a closed silica
tube. After the first ingot had been poured the metal was
allowed to cool until the right temperature was reached and
then the second poured. After a further interval the third was
cast. The following are the actual temperature readings for
two series of castings. The first was made with best selected
Mersey copper (furnace refined), and the second from electro-
lytically refined copper. The latter metal was just as it had
come from the cathodes.
1. 2. 3.
Mersey copper 1445° C. 1225^ C. 1137° C.
Cathode copper 1395° C. 1235° C. 1135° C.
In each of those poured at the highest temperature the metal
rose in the mould.
In order to determine the temperature at which the metal
began to rise or " come back," a thermocouple was put into
the metal immediately after pouring. This took place at a
158 Carpenter and Elam : An Investigation on
temperature just over 1000° C, when the outside of the casting
began to solidify.
For examination, the ingots were cut in half and machined
in a special way devised by Mr. Dewrance, which shows the
crystalline structure and any flaws present. A cut of -poo ^^•
depth is taken with a feed of y^ in. with a very sharp square-
pointed tool Y^ in. wide. This method obviates the use of
etching reagents which in this case would tend to increase the
size of the holes (Fig. 1, Plate VI. ; Fig. 2, Plate VII.).
The most unsound ingot was that poured at the highest
temperature, and was made from Mersey copper. Of those
made from cathode copper, that poured at the highest temperature
was also very unsound but had not risen in the mould to the
same extent as the former. Both those cast at 1235° C. and
1225° C. respectively were perfectly sound, and those poured
at 1135° C. were very good. This emphasizes the fact that it
is very easy to get unsoundness by pouring at a high temperature,
but it is not so easy to err on the other side and get unsoundness
due to pouring at too low a temperature. The blowholes were
bright almost without exception, indicating that the atmosphere
was reducing, not oxidizing. Practically every variety of
copper was tried with the same results. Also it appeared
immaterial whether the melting was carried out in a coke or
gas furnace.
Chill castings poured at three different temperatures showed
considerable differences in crystal size, but they were all
apparently quite free from blowholes. That poured at the
lowest temperature was unsound in the centre, due to piping.
On examination under the microscope, however, that poured
very hot was seen to be full of minute holes. Figs. 3 and 4
(Plate VII.) show the relative size of blowholes in sand and chill
castings respectively.
Provided the metal is allowed to cool in the crucible, hoic-
ever much it may have been overheated, it is obtained quite
free from blowholes. This applies to an alloy made for the
first time or to previously cast metal which is remelted. "This
is to be expected, or sound castings would be unobtainable.
By alternately pouring from about 1400° C. and allowing to cool
in the crucible, the same metal is rendered alternately unsound
Plate VI.
No.
No.
No.
Fig. 1. — Admiralty Bronze Castings, machined to show structure, &c.
No. 1 poured at 1395 C, No. 2 at 1235 C, and No. 3 at 1135 C.
Reduced 46% (of original castings) in reproduction.
[To face p. 15
Plate Vll,
Fig. 2. — Showing method of machining.
Magnification 8 diameters.
Fig. 3. — Sand casting, unetched.
Magnification 150 diameters.
Fig. 4. — Chill casting, unetched
Magnification 150 diameters.
Fig. 5. — Oxide films, unetched.
Magnification 500 diameters.
Reduced 23% in reproduction.
ri_A It V 111.
Fig. 6. — Oxide inclusion, consisting of two
oxides, unetched. Magnification 500 dia.
Fig. 7. — Oxide inclusion, unetched.
Magnification 500 dia.
0 ^
Fig. 8. — Oxide inclusion, unetched.
Magnification 500 dia.
Fig. 9.— Cu.jO light, ZnO dark.
Magnification 500 dia.
Reduced 23% in reproduction.
Wo f 'ice p. 159
Unsound Castings of Admiralty Bronze 159
and sound. The actual casting operation, therefore, provided
the temperature is sufficiently high, is the deciding factor in
producing porous metal. Experiment showed that there is a
drop of about 100° C. in the temperature of the metal in passing
from the crucible to the mould, and this, occurring as it does so
suddenly, is quite sufficient to alter the state of the metal.
From the above observations it w-ill be evident that the
nature of the copper and the various impurities in it have little
or only a minor influence. The temperature, however, is all-
important, and provided this can be regulated and controlled
there should be no difficulty about always obtaining good castings.
The microscopic examination yielded no further evidence
with regard to the formation of blowholes. It did, however,
reveal the presence of a large number of oxide inclusions. These
were often associated with the S copper-tin constituent, and
looked as if they had been pushed there in the process of solidifica-
tion. In addition to these there were fine networks of oxide
films light blue in colour. In Fig. 5 (Plate VII.) these films appear
dark. Some of the oxide had the characteristic blue colour of
cuprous oxide, but by far the greater part was much darker in
colour. This was sometimes associated with the cuprous oxide,
as shown, for example, in Fig. 6 (Plate VIII.), or it existed by
itself in various forms. Fig. 7 (Plate VIII.) shows a large inclusion,
the lighter constituent being the h copper-tin constituent. In
some other cases yet another distinct type was found, which
was either square or rhombohedral-shaped according to the
section (Fig. 8, Plate VIII.). This photograph was taken of a
section of an alloy which had been remelted and recast several
times, and finally contained no zinc whatever. It is very probable
that these three constituents are the oxides of copper, zinc, and
tin respectively.
Zinc and tin act as deoxidizing agents to copper in that they
reduce the cuprous oxide, themselves being oxidized in the process.
Zinc oxide comes to the top and bums off or is skimmed off
together with the tin oxide. If they are not completely removed
they are carried down by the stream of molten metal into the
mould, and are really mechanical impurities. Cuprous oxide,
on the other hand, is soluble in molten copper, and only separates
after the alloy begins to solidify. Provided the amount of
160 Carpenter and Elam : An Investigation on
cuprous oxide in the original copper is not excessive, 2 per cent,
zinc is sufficient to reduce it, so that by the time the tin is added
there should be httle or no cuprous oxide left to reduce.
It is very difficult to distinguish between tin and zinc oxides.
A copper-tin and a copper-zinc alloy were made by melting the
copper and adding the tin or zinc and cooling immediately.
In each was found a dark bluish-grey oxide, so much alike that
it was almost impossible to distinguish between them. The
only difference was in their behaviour to ferric chloride and
hydrochloric acid. The zinc oxide dissolved, whereas the tin
oxide was unattacked. If the heating is continued after the
addition of the tin or zinc, the oxide comes to the surface.
Fig. 9 (Plate VIII.) is a photomicrograph of a section from the
top of a copper-zinc alloy cooled in the crucible showing the
cuprous oxide (Hght) and the zinc oxide (dark) in the oxidized
surface layer of the alloy.
It is a generally accepted fact that blowholes are caused
directly by the evolution of dissolved or trapped gas during the
solidification range, and in the case of copper or its alloys
this gas is generally considered to be oxygen. Steam from
the sand may account for those holes on the outside of the
mould, but cannot be responsible for all. It was decided
that the most suitable way of determining the cause and
possible prevention of porous castings was to investigate the
gas or gases which are actually dissolved and trapped in the
metal.
The solubility of gases has been most fully dealt with by
Sievertg. With regard to the general physical relationships
between gases and metals, he states * that, the temperature
being constant, the solubility of the gases, both in liquid and
solid metals, is proportional to the square root of the pressure.
With rise of temperature the solubility increases, and there is a
large increase at the melting point. For example, one volume
of copper gives off two volumes of hydrogen on solidifying.
In another paper Sieverts f determined the solubility of
various gases in copper at '[a given temperature. He found
that nitrogen is insoluble ^and used it as a standard, so
• Zeitachrift fiir physikalische Chemie, 1911, vol. Ixxviii.
t Berkhte der deutschen chemiichen QeseUschajt, 1910.
Unsound Castings of Admiralty Bronze IGl
that by melting the copper under nitrogen and the gas whose
solubility it was desired to determine, he was able to calculate
approximately the volume of gas absorbed by a comparison of
the pressures in the two cases. According to his experiments,
both carbon dioxide and carbon monoxide are insoluble in
copper.
Sulphur dioxide * is soluble in molten copper in increasing
amounts as the temperature rises, and on solidification 80 per
cent, of the total amount absorbed is retained. Its solubility
is lowered by the presence of sulphur and oxygen OM'ing to the
reversible reaction :
so. + 6Ca ;^ CujS + 2Cu,0.
Heyn.f in a paper on oxygen and copper, proved that the
3xygen exists combined with the copper as cuprous oxide. In the
iquid this forms a homogeneous solution with copper, but is
insoluble in the solid. The eutectic freezes at 1065° C, and has
I composition of from 3 4 to 3 '5 per cent. CugO.
Heyn and Bauer in the paper already referred to have shown
;hat in copper alloys containing tin the oxygen is in the form
)f crystals of tin oxide, which are insoluble in the molten as well
IS in the solid metal. The tin reacts with the cuprous oxide
Dresent with the formation of tin oxide, so that it is impossible
'or cuprous oxide to exist in the presence of metallic tin.
Guichard J attempted to solve the problem by a somewhat
lifferent method. He heated pure electrolytic copper in the
'orm of blocks and wire in vacuo, and analyzed the gases evolved.
Ele only heated the metal to 600° C, and found that the volume
)f gas obtained depended very much on the surface exposed ;
LOO grms. of copper wire gave off 6-56 c.c, of which 62 per cent.
,vas carbon dioxide and 38 per cent, hydrogen and nitrogen,
Detween which he did not distinguish.
Guellemin and Delachanal § estimated the volume and com-
position of the gas obtained by heating certain alloys of copper
md tin in vacuo. The pieces were taken from sound and unsound
'orgings, and the gas consisted of hydrogen, carbon dioxide, and
;arbon monoxide. The sound forgings gave off 90 per cent.
* Zeitachrift fur physikalische Chemte, 1913, vol. Ixzxii.
t Meiallographist, 1903, vol. iv. J Compiu rendiis, 1911. § Ibid., 1908 and 1910.
VOL. XIX. M
162 Carpenter and Elam : An Investigation on
hydrogen, while the unsound gave larger proportions of carbon
monoxide and carbon dioxide.
The work of the last two authors is the nearest approach to
that attempted in the present research.
It was thought that by comparing the volume and composition
of the gases in sound and unsound castings, any differences between
them might give a clue to the problem. In order to do this
sections cut from the castings were melted in vacuo, and the gases
given off collected and analyzed. The apparatus consisted of a
fused silica tube, closed at one end, the other end, which protruded
6 in. from the furnace, being connected to glass tubing by means
of a greased ground-glass joint. This was kept cool by a spiral
of flexible tubing through which water flowed. By means of
glass tubing the silica tube was connected to a barometer and an
automatic Sprengel pump designed by our colleague. Professor
W. A. Bone, F.E.S., who also assisted us by his advice as to the
method employed for extracting and collecting the gases (see
Fig. 10). A vacuum of from 0*5 to 1 mm. was obtained. It
was difficult to reduce the pressure further, owing to the difficulty
of drying the apparatus sufficiently. All drying tubes had to
be arranged so that they could be completely shut off when it
was desired to collect gas from the metal. The apparatus was
perfectly air-tight even at 1200° C.
The weight of metal melted was from 70 grms. to 150 grms.,
according to requirements. This was placed in an alundum boat
in the silica tube. The furnace was a platinum wound tube
furnace and was mounted on rails, so that it could be slipped on or
off the silica tube as desired, thus enabling the metal to be cooled
quickly or slowly. In this way it was also possible to observe
the metal at any moment. Unfortunately, owing to the diffi-
culties of manipulation, it was impossible to have a thermocouple
actually registering the temperature of the metal. The tempera-
ture of the furnace being known, however, it could be kept con-
stant a sufficient length of time to enable the metal to reach that
temperature also.
Some preliminary experiments were carried out to ascertain
the volume of gas that was likely to be obtained. The metal
was heated to 1100° C. and in some cases to 1200° C, and main-
tained at that temperature for half an hour. The gas did not
Unsound Castings of Admiralty Bronze 163
a
>.
I
p.
164 Carpenter and Elam : An Investigation on
always all come off on the first heat, and sometimes two or even
three melts were necessary before on further heating there was
no change in pressure. A chill casting was an interesting example
of this. The metal was heated until no further gas came o&.
On examining it after cooling, it had the appearance of an un-
sound sand-casting, the surface had risen and it was full of large
l)lowholes. On heating further more gas came off. Trials
were made of a silica boat for holding the metal, but this had
to be discarded as bubbles of gas collected between the boat and
the under surface of the metal and remained there. The gas
could not force its way out even at the reduced pressure, and the
character of the solidified metal showed where these bubbles had
been. This demonstrates that the gas does not readily escape
from the metal. The volume of gas obtained was calculated from
the increased pressure, as observed by the barometer tube, the
volume of the whole apparatus having been previously deter-
mined. There were considerable variations in the volume of
the gas obtained from pieces cut from the same ingot, the average
volume from a sand-casting poured at 1445° C. being about 4*5 c.c.
per 100 grms. (about 12-5 c.cm.) of metal. A chill casting gave
approximately the same amount, and a sand-casting poured at the
right temperature generally a little less. The gas began to come
off at about 450° C. from a sand-casting ; that from a chill casting
at about 750° C. The evolution, when once begun, continued
regularly up to the melting point, at which temperature it practi-
cally ceased. There was no sudden absorption or evolution at
that point. A large proportion of zinc volatilized on the sides
of the tube. In some cases only a trace remained in the alloy.
There was also a black substance which deposited. On dissolving
all the deposit off with nitric acid, sulphur separated, while with
hydrochloric acid there was a strong smell of hydrogen sulphide.
Probably there is present a mixture of zinc, zinc sulphide, copper
oxide and copper sulphide, and free sulphur. There was con-
siderably less sulphur from the alloy made from cathode copper
than from any other. As will be shown later, the zinc is chiefly
responsible for combining with the sulphur, and deposits on the
sides of the tube as zinc sulphide.
The tin does not appear to be affected in this way.
On cooling small beads of metal are ejected. If the furnace is
Unsound jOastmgs of Admiralty Bronze 165
removed, so that the tube and metal cool quickly, a film of cupric
oxide is deposited on the inside of the tube immediately abovo
the boat, and sometimes also on the surface of the ingot. This
only occurs if the furnace is removed while the metal is molten.
If the tube cools slowly in the furnace, any cupric oxide so formed
volatiHzes and collects outside in the cooler parts, together with
the zinc. This suggests that oxygen in some form is liberated on
cooling, and that it can be retained in solution even at a pressure
of only a few millimetres. It does not, however, make the metal
unsound. Any oxygen given off by the alloy, along with the
other gases, immediately forms cuprous or cupric oxide and can
never be collected as a gas. Either it exists as oxides of copper,
tin, or zinc, or it may be formed by the decomposition or interac-
tion of certain other gases present. There is a small amount of
oxygen in some of the analyses, which may come from the gases
in the metal or from air in the mercury or a small leak, &c.
This also applies to the nitrogen.
The density of the metal gives a decided indication of the
degree of unsoundness. There are considerable variations in the
same casting according to whether the metal is cut from the
outside or the centre. Below is a list of the densities of some
castings of the composition 88 per cent, copper, 10 per cent.
tin, 2 per cent. zinc. :
Nature of Copper and Mould.
1. Mersey copper, sand .....
2. Cathode copper, sand .....
3. Cathode copper, sand .....
4. Mersey copper, sand .....
5. Mersey copper, chill .....
6. Cathode copper. Nos. 2 and 3 melted in vacuo
Pouring
Temperature.
Density.
Dcg. C.
,8-2
1445
81
7-79
I 7-2
1.395
8-34
1235
8-69
1137
'JOO
14C0
8-73 and 8-8
8-85
The gas analyses were carried out by Messrs. E. J. Sarjant,
B.Sc, and C. C. Smith, A.E.S.M., in the Department of Chemical
Technology, upon a Bone and Wheeler apparatus for mine air
analysis, specially designed for the accurate analysis of small
volumes of gas.
When it came to collecting the gas fur analysis a very much
166 ^ Carpenter and Elam : An Investigation on
Bmaller volume was obtained thau had been expected from the
calculations. It was found that the volume varied according to
the time taken in removing the gas. Not only did the volume
vary, but the composition varied also. The following are two
analyses of gas collected from adjacent pieces of the same casting ;
in the first the pump was started simultaneously with the heating,
and in the second the apparatus was allowed to cool before being
evacuated. Hence in the latter the gas was in contact with the
hot metal for a considerable time, and its various constituents
had a chance of reaching an equilibrium.
I. n.
Per Cent. Per Cent.
Sulphur dioxide or hj-drogeu sulphide . . . 15-6
Carbon dioxide ....... 3-4 5-8
Carbon monoxide ...... 57-6 41-3
Hydrogen ........ 7-6 41-0
Saturated hydrocarbons ..... 2-9 1 -9
Unsaturated hydrocarbons ..... 2-4 0-9
Oxygen ........ 11 1-2
Residual gas, nitrogen ...... 9-4 7-8
Volume of gas collected per lOOgrms. metal at 0^ C.
and 760 mm 217 c.c. 3-65 c.c.
It will be seen from the above that the larger volume is asso-
ciated with a large proportion of hydrogen, whereas the smaller
has very little hydrogen and a considerable quantity of sulphur
dioxide and sulphuretted hydrogen. This is true for all the
analyses that have been done. The facts then are these : if, on
the one hand, the gas is removed as quickly as it comes off, it
has a smaller volume, its chief characteristics being a large per-
centage of sulphur dioxide and hydrogen sulphide and a small
percentage of hydrogen ; if, on the other hand, the gas is removed
slowly or heated for a long time in contact with the hot tube and
metal, the volume is larger than in the former case. There is
then a large percentage of hydrogen, and the sulphur dioxide and
hydrogen sulphide are either low or entirely absent. It follows
necessarily that there are intermediate stages with varying pro-
portions of these constituents corresponding to variations in the
volume.
The zinc volatilizes when the alloy is heated, and is no doubt
responsible for the absorption of the sulphur from the sulphur
dioxide and hydrogen sulphide when the gas is left in the heated
tube for some time. Even if it is removed as quickly as possible
Unsound Castings of Admiralty Bronze 167
only a portion of these gases is collected. To show this more
clearly, an alloy was made containing 89 per cent, copper and
11 per cent, tin, the gas from which gave the following
analysis :
Hydrogen sulphide or sulphur dioxide
Carbon dioxide .
Carbon monoxide
Hydrogen .
Satuarted hydrocarbons
Unsaturated hydrocarbons
Residual gas, nitrogen .
Volume of gas collected per 100 grms. metal at 0' C. and
760 mm.
Per Cent.
53-4
61
27-4
nil
1-4
1-7
1-4
10-6
1-44 c.c.
It seems likely, however, that the zinc not only reacts witir
the sulphur dioxide and hydrogen sulphide during the experi-
ment, but that it also lessens the solubility of these gases in the
alloy. Below are two analyses of the gases evolved from pure
copper (Bio Tinto best selected), somewhat overpoled. In the
first the gas was heated to constant volume. In the second
it was collected as quickly as possible. They most nearly re-
semble the analysis of the gas from the copper-tin alloy just
given, and since they are so much alike they emphasize still
further the important part played by the zinc in altering the
volume and composition of the gas collected from Admiralty
bronze. In neither of these was there any free hydrogen.
Hydrogen sulphide or sulphur dioxide
Carbon dioxide .
Carbon monoxide
Hydrogen .
Saturated hydrocarbons
Unsaturated hydrocarbons
Oxygen
Residual gas, nitrogen .
Volume of gas collected per 100 grms. metal at
0° C. and 760 mm
Gas Collected
Quickly.
Percent.
70-9
19-6
4-7
Gas Collectec
Slowly.
Per Cent.
61-2
34-9
0-8
1-2
2-8
11
2-8
4-45 c.c.
6-95 c.
In these cases there was not much cuprous oxide in the copper,
and very little oxide was found on the tube on heating.
On the whole, a smaller volume of gas was generally collected
from the sound metal, but this was by no means always the
case, and it was very difficult to make comparisons between
168 Carpenter and Elam : An Investigation on
them owing to the uncertainty of exactly reproducing the con-
ditions in each case. The only way in which such a comparison
could be made was by heating the gases in the tube to constant
volume. Sound and unsound metal poured in one case from the
same crucible gave 6*44 c.c. and 5-95 c.c. respectively, calculated
for 100 grms. metal at 0° C. and 760 mm.
As it was considerably more difficult to ensure the same
conditions when removing the gas quickly, owing to different
rates of heating and variations in the working of the pump, it
seems fairest to compare the analyses of gas samples collected
after cooling, when these variations do not matter. The inter-
action of the gases is not very rapid even at 1100° C, but pro-
vided the metal is maintained at that temperature for a sufficient
period the reaction is complete. In all these experiments the
apparatus was allowed to cool before being evacuated.
The following is a series of analyses of gases obtained by
heating certain pieces of castings until apparently all the gases
had been evolved. There is a considerable difference in the
volumes obtained, and it will be noticed that the largest volume
of all was obtained from a sound casting poured at the right
temperature.
Gas heated for Half an Hour in the Apparatus before Removing.
Sand Cast.*
ChiU Cast.*
Sand Cast.*
Sand Cast, t
1
SandCast.ti
Mersey.
Mersey.
Mersey.
Cathode.
Cathode. I
Pouring temperature
1400° C.
1400° C.
1225° C.
1236° C.
1395° C.
Sulphur dioxide or hydrogen .
sulphide ....
4-6
10-2
2-0
Carbon dioxide
5-8
7-6
9-3
10-0
4-5
Carbon monoxide .
41-3
32-4
19-8
20-6
25-2
Hydrogen , ' .
410
50-2
56-7
62-9
56-9
Saturated hydrocarbons
1-9
0-9
11
• 10
30
Unsaturated hydrocarbons
0-9
1-5
1-2
0-6
0-8
Oxygen ....
1-2
0-9
0-9
Residual gas, nitrogen .
7-8
7-4
6-3
3-9
7-6
Volume of gas collected per
;
100 grms. at 0° C. and
760 mm
3-65
2-88
4 08
2-66
3-53 i
1
♦ None of these three was cast at the same time.
t Ihesa two were poured from the same pot with about 5 mins. intcrral.
Unsound Castings of Admiralty Bronze 169
The most constant characteristic of all these gas samples is
the large percentage of hydrogen. Allowing for probable errors
in the analyses owing to the small volumes of the gases — seldom
more than 3 or 4 c.c. and sometimes less — and for variations
in the experiments and for differences in the preparation of the
castings, &c., there is no outstanding difference between the
gases collected from sound and unsound castings which would
account for the absence of blowholes on the one hand, and the
presence of blowholes on the other hand. The gas that shows
the greatest variations is carbon monoxide, but there is nothing
to indicate that it has any relation to the unsoundness. Taking
everything into consideration, it cannot be concluded that there
is any gas present in the metal poured too hot that is not in the
sound metal, nor does it appear that there is a larger volume
of any one gas or gases present in the one than in the other.
It does not follow that this is the case when the metal is at different
temperatures, and it only applies to the gases when they are
collected in this particular way, which represents their equilibrium
stable at 1100° C. under the conditions of the experiment.
The fact that the metal is melted in vacuo and that the zinc
volatilizes must have a marked effect upon the gas reactions.
For that reason alone it might be fairer to take the gas samples
collected as quickly as possible as being more representative
of the gases in the metal. For reasons already given, these do
not show the same agreement as the others.
Gas removed from tlie Apparatus as Quickly as Possible.
Nature of copper ..... Cathode.
Cathode, i Mersey. Mersey.
Pouring temperature .... 1396° C. 1235° C. 1400° C. 1237° C.
Sulphur dioxide or hydrogen sulphide
Carboa dioxide
Carbon monoxide .
Hydrogen
Saturated hydrocarbons
Unsaturated hydrocarbons
Oxygen
Residual gas, nitrogen .
Volume of gas collected per 100 grms,
metal at 0° C. and 760 mm.
8-7
15-3
211
23-9
3-3
2-1
0-9
24-7
16-9
15-6
27-6
9-2
1 3-4
6-6
21-6
57-6
41-6
31-4
7-6
3-9
1 2-9
2-6
2-4
2-i
0-8
11
0-4
14-6
9-4
21-7
1-0 c.c. 2-33 c.c. 1-9 c.c.
170 Carpenter and Elam : An Investigation on
All the errors of analysis are found in the last figure of the
columns, together with the actual amount of nitrogen present.
The error is necessarily greater when dealing with such small
volumes.
These analyses may be considered in relation to alloys made
from cathode copper and those made from Mersey copper. As
would be expected, the hydrogen is high in that made from
cathode copper. On the other hand, these differences disappear
when the gases are collected in the other way, as the previous
table shows. As the bronze is liable to be unsound irrespective
of the copper used, it follows that these analyses can hardly
represent the composition of the gas which makes the blowholes.
It is remarkable that there is no free hydrogen in the copper
to begin with, and that it is entirely absent or very low if the
gas is removed quickly from the apparatus. Where does the
relatively large volume of this gas come from, which appears when
the evolved gases are maintained at 1100° C. in contact with the
hot metal for some time ? Some of it obviously is formed by
the decomposition of hydrogen sulphide, since in all the gases
investigated a small volume of the one is always associated
with a relatively large volume of the other. Hydrogen sulphide
decomposes at 400° C. into its elements after which the zinc
unites with the sulphur forming zinc sulphide, and the hydrogen
is left free. On the other hand, sulphur and hydrogen combine
at a high temperature, making the reaction reversible.
The large volume of hydrogen may be due to the dissociation
of water formed by the combustion of hydrocarbons, with a
simultaneous formation of carbon monoxide and carbon dioxide.
It may also be due to the decomposition of certain hydrocarbons
yielding two or three times their volume of hydrogen. The
nature of the gas is so complex and its possibilities of reacting
so numerous that it is difficult to formulate any hypothesis
with confidence as to its behaviour at such a high temperature
and under such exceptional conditions. One fhing at any rate
is certain, namely, that this mixture of gases can exist in more
than one form, each fossessing its characteristic volume and
com'position. It must not be forgotten, however, that the gas
mixture with the smaller volume could not possibly change
into the gas mixture with the larger volume by merely heating
Unsound Castings of Admiralty Bronze 171
it for any length of time. The presence of the hot metal is
necessary, and even this must have a chemical and not a catalytic
action.
Any differences in the total volume of gases collected from
sound and unsound metal do not appear large enough to warrant
the conclusion that the blowholes in metal poured too hot are
caused by a total larger volume of gases soluble at that
temperature but insoluble at a lower temperature. Nor is
there any evidence for stating that one particular gas, which is
soluble at a high temperature but comes off as the metal cools
to the correct pouring temperature, is the cause. The fact
that it is very difficult to extract the gases from this metal, under
any circumstances, points to another reason altogether. The
explanation which appears most probable to the authors is based
on the fact which they have established, that more than one
volume and composition of the gases occurring in Admiralty
bronze is possible. It seems reasonable to suggest that the sudden
change of temperature in the alloy, due to pouring at a very high
temperature, is sufficient to cause a reaction or a decomposition
of certain of the gases, with the formation of another gas mixture
with a relatively large volume which is insoluble in the alio}'.
At a lower temperature the gases are not so susceptible to this
change, and those jDresent in the metal remain in solution. Com-
paratively little work has been done on the reactions of gases
at high temperatures, and practically nothing at the casting
temperature of Admiralty bronze, so that it is impossible to
predict the action of the very composite gas which has been
found in this metal. Pending this no complete scientific explana-
tion of the unsoundness liable to occur in Admiralty bronze
can be put forward.
Practical Considerations.
It is clear from the foregoing investigation that, provided
Admiralty bronze (88 : 10 : 2) is not poured at too high or too
low a temperature, there should be no difficulty in obtaining
sound castings. The upper limit of 1270° C. and the lower
limit of 1120° C. fixed by Karr and iiawdon should be borne in
mind in this connection. Although the authors have not tested
172 Carpenter and Elam : An Investigation on
these precise limits their results are, generally speaking, in harmony
with them. The problem ilierefure is esseniially one of tempera-
ture control and nothing else. How can this best be practically
achieved ?
Three ways at any rate suggest themselves for consideration :
(1) To melt and cast the alloy so that no contamination by j
gases is possible.
(2) To regulate the temperature of the melting furnace so
that the upper limit of 1270° C. is under no circumstances exceeded.
(3) Always to determine the temperature of the alloy before
it is poured and to cast it within the safety range.
Method 1. — This appears to the authors the least promising
of the three. It might be considered on a 'priori grounds that
success could be reached by melting the alloy in an electric
furnace. The only certain ^^ay of excluding gases from the
outside in this case would be to melt and cast in vacuo — a method
which can at once be ruled out on practical grounds. P]ven
this, however, if successful from this standpoint, would not
constitute a complete solution, for the reason that it takes no
account of the gases contained in the copper used in the production
of the alloy. On the one hand, furnace-refined — as distinct from
electro-deposited — copper contains sulphur dioxide, hydrogen
sulphide, oxides of carbon, and some oxygen, and is bound to
do so from its method of manufacture. Cathode copper, on the
other hand, contains hydrogen, which is liberated with the copper
at the cathode. It may also contain, and usually does, traces
of mechanically imprisoned copper sulphate from the electrolyte,
which on melting would give rise to sulphur dioxide. A large
proportion of cathode copper, however, is subsequently furnace
refined in order to bring it to pitch, and is therefore exposed to
the same sources of gaseous contamination, as have been mentioned
above. The authors' investigations have shown how difficult
it is to remove these gases even in vacuo. It is obvious, there-
fore, that this difficulty w^ould always be present whichever
brand of commercial copper were used, and whatever the method
of melting adopted. Any practical solution nuist take account
of those facts.
Method 2 has more in its favour. That the furnace
temperature should not exceed 1270° C. would mean less fuel
Unsound Castings of Admiralty Bronze 173
consumption, and the importance of this would be great. Against
this, however, should be set the fact that the rate of melting
would be diminished, and this would lower the output of the
furnace. (The temperature of the furnaces in the foundry of
Messrs. J. Dewrance & Co. was at least 1500° C.) Moreover, it may
fairly be argued that this method involves the measurement and
regulation of temperature, and that it is preferable to carry this
out on the alloy and not on the furnace which is merely melting
it. No matter how uniform the temperature of the furnace
and the period of melting were maintained, there would always
be some uncertainty with regard to the temperature of the metal,
particularly on account of the fact that additions of zinc and
tin have subsequently to be made in preparing the alloy. For
those reasons it appears to the authors that
Metlwd 3 has the most to recommend it jrom a 'practical
standpoint, i.e. the temperature of the bronze should alicays he
determined before it is poured, in order to be certain that when
cast it is ivithin the safety range (1270° to 1120° C). This
involves the use of a pyrometer, which can be depended on to
give reliable readings of the temperature of the metal. Such
pyrometers now exist, and are widely used in the industries.
Those who are interested in this question can obtain a great
deal of valuable information with regard to the most suitable
pyrometer to be used in any given case, by studying the papers con-
tributed to the general discussion on pyrometers and pyrometiy
at the Faraday Society on November 7, 1917. The extent to
which pyrometers are now used may be judged by the fact that
" one armament firm alone has six hundred instruments in daily
use." *
For measurements up to 1200° C. the pyrometers used are
principally thermo-electric ; above this, optical and total radiation
pyrometers are generally employed. The latter class, therefore,
would probably be more suitable in this particular case, because
the metal has to be heated well above 1200° C. The discussion
at the Faraday Society elicited the fact that steel-makers now
attach great importance to the pouring temperature of steel, which
is about 1600° C. This is a much more difficult problem than
that of pouring Admiralty bronze within the safety range. In
the former case, quite apart from the difficulty of working at
* Nature, 1917, p. 212.
174 Carpenter and Elam : An Investigation on
much higher temperatures, attempts are made to keep the casts
within 10° to 20° C. of the required figure ; in the latter there
is a range of about 150° C. within which sound castings can be
obtained.
The three methods whose possibihties have been briefly
considered are all of a physical nature. A fourth method, whose
possibility has not been dealt with in this paper, is essentially
chemical in character, and would consist in endeavouring to
expel the dissolved gases in the alloy before pouring by the
addition of reagents. Several of these are on the market, and
it would be interesting if experience with regard to their success
or otherwise were forthcoming. The authors are themselves
carrying out tests of this kind. The pouring of the alloy within
the safety range of temperature, however, would render all such
expedients unnecessary, and appears to the authors a moi e
preferable practical solution.
Summary and Conclusion.
1. The best casting temperature for Admiralty bronze is
about 1200° C. Overheating to 1400° C. and pouring at that
temperature is certain to produce porous castings. Pouring
below 1100° C. very often produces unsoundness.
2. The nature of the copper appears to have little or no
influence on the final results.
3. Metal melted and cooled in the crucible is sound, even if
it has been overheated to 1400° C. This also applies to previouslj^
cast unsound metal.
4. The blowholes are formed by the liberation on cooling of
gases dissolved in the metal.
5. The gas collected by heating pieces of castings in vacuo
is of a complex nature, consisting of the typical furnace gases.
6. Its volume and composition vary with the method of
collection, depending on the time the gas remains in the furnace.
The two types are :
{a) The gas is removed quickly. In this case it has a
small volume. There is very little hydrogen and
generally a fair proportion of sulphur dioxide and
hydrogen sulphide.
Unsound Castings of Admiralty Bronze 175
(6) The gas is heated to constant volume or removed
only slowly. In this ease the volume is much larger.
There is a large percentage of hydrogen — about 50 per
cent. — and the sulphur dioxide and hydrogen sulphide
are either very low or entirely absent.
7. The zinc is largely responsible for this change, as there
is much less difference in the gases collected in the two ways
from pure furnace-refined copper. It may act in two ways :
(a) It may lower the solubility of these gases in the alloy.
{b) By volatilizing in vacuo it reacts with the sulphur
forming zinc sulphide, and this condenses on the
inside of the tube.
8. A gas of approximately the same composition is found in
both sound and unsound sand-castings and in chill castings.
There is not a constant or sufficient difference in the volume of
gas obtained from unsound and sound castings to account for the
presence of blowholes in the one and their absence from the other.
9. It does not seem likely that the blowholes are formed
by the liberation of oxygen, as all the oxygen present in the metal
is in the form of oxides of zinc, tin, or copper, if there is much
present, the first two of which are very stable compounds and
not at all likely to decompose when once formed.
10. The analysis of the gas obtained by heating pure copper
very much resembles that of the gas obtained from a copper-tin
alloy, and this suggests that the gases which cause unsoundness
in the alloy are actually in the copper itself. The volumes of
these gases are also about the same.
11. When once the gases are in the metal it is very difficult
to extract them.
12. The most suitable practical way of avoiding porous
castings would appear to be to determine the temperature of
the alloy so as to ensure that it is poured within the range (1270°
to 1120° C).
The authors have pleasure in acknowledging the advice and
the assistance of Professor Bone and the staff of the Department
of Chemical Technology in connection with the collection and
analyses of the gas samples.
176 Discicssion on Carpenter and Elam's Paper
^ DISCUSSION.
Professor T. Turner, M.Sc, Vice-President, who took the Chair
whilst the President's joint paper was being discussed, said that among
the many things which were interesting to the members in connection
with the paper he was sure there was one which he might mention at
once, and that was the fact that for the first time in the history of the
Institute of Metals a lady had presented a paper. When the character
of the work and the way in which the subject had been presented were
considered, he was sure the members congratulated Miss Elam upon
occupying the position.
Mr. Dewrance had taken a great deal of interest in the work, and
he would ask him kindly to open the discussion.
Mr. J. Dewrance, Member of Council, expressed the extreme regret
he felt that the value of the paper would be interfered with to a large
extent by the restrictions owing to the shortage of paper. It was a
paper which he thought should be printed and reprinted and distributed
among all the bronze foimders throughout the kingdom. Though to
a large extent the information and the results were negative, it was
to ordinary founders a very important thing that they should know
exactly the character of the enemy and where the enemy was, and
should know that they had not to look for him in places hitherto
sought in and which had been so very largely surrounded with
mystery.
The tendency in the past had been to regard the subject in a very
different way to that in which it was presented by the authors that
evening, and he was sure that the extreme simplicity of the language
and the very conclusive results which had been presented would be of
inestimable value to all practical founders.
Miss Elam had mentioned particularly the very great value of
the pyrometer. In relation to that he thought the members must
remember what transpired before the adjournment, when the President
exhibited a very great penchant for the pyrometer and one of the
members defended the non-use of it. He was at the shell works of
a Company of which he was Chairman a httle time ago, and he found
that a pyrometric record was being made of every shell that was forged
of 12 in. in diameter and above, and he said to the manager, " If this
is necessary and right, surely it should be applied to all shells." He
said, " Oh, you could not possibly apply it to. the thousands of small
ones we are making." That was the view of the ordinary founder.
There could be no doubt that the results which the authors had
presented could not have been presented satisfactorily without the
Discussion on Carpenter and Elam's Paper 177
use of the pyrometer, and personally he hoped that the use of the
pyrometer would be extended very considerably. At present there
was not a pyrometer which ^the^^authors could trust in the hands of
foremen who were at present employed in the foundry, and actually
to take a pyrometric record of every cast of metal, having regard to
the large number that were made, was a question of balance of ad-
vantage and disadvantage which it was not necessary to go into further
at the present moment. But there was one point which he thought
everybody would agree upon, and that was that while Professor
Carpenter was extremely surprised at the very great accuracy with
which the practical founder was able to forecast the record of the
pyrometer, the practical founder was, on the other hand, extaremely
surprised that Professor Carpenter was able with his pyrometer to
ascertain exactly what he, the founder, was able to ascertain by obser-
vation. These two circumstances were of very great benefit to the
practical founder. They gave him a degree of respect for the scientific
side of his calling that he could not have obtained in any other way,
and therefore the frequent use of the pyrometer in the foundry, if it
was only for experimental or checking purposes, was of enormous
practical advantage. Though it might not be applied to every cast,
there should be a certain number of check casts with pyrometric
records which would educate the observations of the practical men
and make them more accurate than they had been in the past.
It was to that point that he wanted particularly to call attention,
that the object of the paper, or one effect of the paper, might be ex-
tremely valuable, and that was to show first of all that the castings
must be made within a certain range of temperature, and, secondly,
that that range of temperature must be very accurately observed
either pyrometric ally or as the result of pyrometric education.
The actual paper did not in any way give any idea of the amount
of work they had expended on the research, but it did, he thought,
accurately represent the state of their present knowledge. He very
much hoped that it did not in any way represent the knowledge that
they were going to obtain. What practical founders wanted was
something that would increase the range of temperature, and they
wanted something which they could put into the metal which would
liberate the gas and enable them to pour the metal in a wider range
of temperature. If the authors could pursue their investigations
with that object in view and succeed in obtaining such a result, foundry-
men would have cause to be even more grateful to them than they
were to-day.
Commander C. F. Jexkin, R.N.V.R. (London), said that he had only
read the paper very hurriedly, but he had read it with the very greatest
interest. It concerned one of the standard alloys which was used by
the Air Board. He thought that he could get over the difficulty of
shortage of paper which was referred to by Mr. Dewrance, because
VOL. XIX. N
ITS Discussion on Corpenter and Elanis Paper
in the position he held he was able to issue instructions to all the
foundries who were using any of the alloys, teUing them exactly what
they had to do, and his present intention, formed rather hurriedly,
was to issue instructions at once showing how sound castings might be
obtained. One other point which he was particularly interested in,
and which he should very much like to ask i\Iiss Elam if she would
tackle at once, was what he imagined to be a closely allied alloy,
phosphor-bronze, which contained practically the same elements
minus the zinc and plus a trace of phosphorus. At the present moment
there were difficulties owing to slight imsoundness in phosphor-bronze
castings. He had not the least notion how to get over this defect,
but it possibly might be just as simple in its cui'e as had been the
matter of the Admiralty bronze castings. If that question could be
tackled at once, it would be of great and immediate value. The
particular use for which the castings were employed, and where the
unsoundness gave so much trouble, was the seats for the valves in
aeroplane engines. Very minute porosity or want of perfect soundness
on the seat of the valve would obviously allow the hot gases to leak
at that point ; the leak very rapidly burnt out and the engine came
to grief. Sound castings could not be obtained at present, and other
alloys had to be used which were very likely less satisfactory. He
hoped, therefore, that phosphor-bronze would be investigated at
once.
Mr. M. Thornton Murray, M.Sc. (Birmingham), said that at the
outset he would hke to congratulate the authors upon the accom-
plishment of a very painstaking piece of research, and the pubhcation
of results having a very real theoretical, but chiefly practical utility.
He would like also to congratulate them upon a very admirable re-
ticence in the interpretation of the results obtained. He did not
mean that in any way in a sarcastic sense, but he agreed with the
authors in their remark on p. 171 that pending certain other investiga-
tions respecting the interaction of gaseous mixtures at high temperatures,
no complete scientific explanation of the unsoundness liable to occur
in Admiralty bronze could be put forward. More than that, he would
venture to say that the remark on p. 159, that, pro\'ided the tempera-
ture can be regulated and controlled, "there shoidd be no difficulty
about always obtaining good castings," was, in view of the compara-
tively restricted field covered by the research, somewhat daring. He
had had a good deal of experience in casting this metal, and while he
admitted that the question of the temperature of casting was a very
important one, he had found that certain other factors had to be
seriously considered, before arri\'ing at the happy position of being
able to guarantee all his castings as good. Perhaps much of the
difference be' wern his own point of ^'iew and that of the authors lav
in a definition of the term " sound." He could have wished for a
statement of the sense inwhich they were now using that term. As a
Discussion on Carpenter and Elani's Paper 179
matter of fact, since he had seen the actual castings he had found out
the sense in which it had been used. Some other causes of failure
in castings had, it was true, been mentioned or investigated in the
paper ; notably oxide inclusions and films. But his own practical
experience had shown that that particular alloy was susceptible
to " all the ills that alloys were heirs to." Shrinkage cavities were of
very frequent occurrence, unless great care was taken in the feeding
of complicated castings. Segregation, especially in large bodies of
metal, was liable to occirr if means were not taken to combat it, and
segi'egation of a very injurious nature. He could have wished, there-
fore, that the authors had submitted physical tests of their castings
alongside the other data which they had supplied. He was not entirely
persiiaded, either, that porosity is invariably and solely due to gas
bubbles (c/. Primrose's inter crystalline pores, referred to by the authors,
which he attributed in his paper largely to the mode of occurrence of
the 8 constituent, and which he was able to cure by suitable annealing).
Hydraulic tests would also have been of considerable value. They
ought not, he knew, to look a gift horse in the mouth, or to criticize
the donor when giving horses, especially when the giving of horses
was the least of his many war-time activities, and he was grateful
for the information which had been afforded by the authors. But
he would have been more comfortable in mind if the authors could
have assured him — ^perhaps they could and would in their reply —
that the alloys cast between their limit temperatures would have
been of uniformly high strength and ductility, and would have been
able successfully to withstand hydraulic pressure, and that those
cast at other temperatures would not. After examining those shown,
he must say that that remark was almost answered, because he should
think that they would stand anything, but it was rather difficult to
see that from the photographs supplied in the paper. With regard to the
actual methods of measming the temperature of the pots of the molten
metal (Admiralty gun-metal), he had found in practice considerable
difficulty. He had tried the ordinary platinum-platinum-rhodium
or platinum-platinum-iridium couple, and had found it excellent up
to a point. But in a large foundry where many heats were cast per
day he experienced very great troiible with suitable protectors. Steel
sheaths were quickly corroded through after about a dozen immersions.
A check test was exceedingly valuable, but the same thing applied
to the application of check tests, or rather the neglect of tests on every
pot, as applied to Mr. Dewi'ance's point in regard to the shells. This
might have been of no great importance — that was, the corroding
of the sheaths — ^had not each accident been accompanied by the
formation of an alloy of copper-tin-zinc-platinum-rhodium, which was
no doubt of great metallurgical interest, but of little market value.
Non-metallic sheaths, which he had tried, were of course of very little
use, owing to the great lag and the long time it was necessary to wait
before the temperature was obtained- On the other hand, radiation
180 Discussion on Carpenter and Elam's Paper
pyrometers generally gave erroneous readings (according to a paper
read by Mr. C. M. Walter at tlie Birmingham local section on March 6,
1918) when used on molten copper alloys containing zinc, owing to the
zinc fume. He had not yet had an opportunity of consulting the
reference which the authors gave on this question, but he should
certainly do so at the earliest opportunity. He had, however, been
in touch with the makers of pyrometers with, he confessed, no great
hope of success. The materials used, according to the authors —
particularly the copper — ^made little difference to the prevalence or
otherwise of blowholes. That was of interest in that many foundry men
insisted upon copper of certain brands for making Admiralty bronze
castings, maintaining that the presence of certain impurities materially
affected the properties of the casting. If that was a superstition, it
was well that it had been quashed, but he had certainly met cases in
which certain brands of copper had given consistently higher physical
tests in the gun-metal made from them than was normally the case.
Might not such a condition be due to the effect exercised by those
impurities upon the solubility of the absorbed gases in the metal or
upon the equilibrium of the gaseous mixture mentioned by the authors ?
That was just an idea, but he should like to see fmther investigation
upon those lines. With regard to the point about oxygen in copper,
he presumed that was a superstition of the foundry, because of course
an inspection of the surface of the vesicles in a pure cast copper would
show at once that the gas could not possibly be oxygen. An analysis
of the copper which was vesicular generally showed no increase in
the oxygen content over a copper which was closely grained, and
further than that, the copper which was vesicular had in his experience
generally been cast at a low temperature. That was rather an interest-
ing point : that the vesicular copper was obtained by casting at too
low a temperature, whereas the authors pointed out that Admiralty
gun-metal was made porous by casting at too high a temperatui-e.
Then the information which the authors gave as to the composition
of the gases was of great practical as well as theoretical interest. Once
and for all to have identified the gases in this metal (and he took it
that with some reservation it might be concluded that the gases in
other copper-tin-zinc alloys would be similar in composition), to have
identified those as furnace gases, Avas no small achievement, and casters
of non-ferrous alloys would be grateful to the authors for their paper
for that reason alone, if for no others. The analysis showed much
skill, and the errors as shown by the nitrogen figures were remarkably
small considering the tiny volumes of gases obtainable. He could
not quite account for the extraordinarily high hydrogen values of the
second — that was, the slowly extracted — mixture. Even if it were
supposed that the gases returned as SHo and SO^ were wholly •
SHa, and the hydro-carbons were exceptionally rich in hydrogen, he
could not make up the largely increased volume of hydrogen in, say,
Discussion on Carpenter and Elams Paper 181
column 2 of the table ou p. 166 from the figures given in column 1. He
was at a loss to supply another explanation, but he felt that it
was a very important point, which should, if possible, be further
investigated,.*
Professor C. A. Edwards, D.Sc. (Member of Council), said that it
had been clearly indicated by the authors that, in order to produce
sound castings, the metal must be cast within a proper range of tem-
perature. He knew^ that they were in some difficrdty in the direction
of suggesting how those temperature ranges should be regulated. That
was a difficulty that all metallmgists were up against, viz. the accui'ate
determination of temperatures. In the present case he thought there
was a possibihty of overcoming the difficulty as regards pyrometers.
He did not say that the suggestion that he proposed to make was one
which would be adopted immediately, but he thought, in view of the
importance attached to casting temperatures in the near future, there
■would be such developments as he was going to suggest. The one
great difficulty in foundry practice in the control of temperature
measurements was the fact that men were dealing with comparatively
small masses of metal so very frequently throughout the day, that
the application of pyrometry was a very difficult matter. They
were dealing possibly with small crucibles which, even after they had
made their temperature measurements, had to be carried through
fairly long distances in the foundry. Now that was a practical difficulty
which all foundry people were always advancing in opposition to any
such paper as that of the authors. That difficulty could, he thought,
be overcome in this way. Why not have an electrically wound re-
sistance furnace almost round the crucible itself, sunk in a carriage
which was capable of being wheeled throughout the whole foundry,
having a loose trolley wire such as was used on the ordinary car track,
and regulate the resistance of that furnace in such a way that the
temperature would be kept absolutely constant ? Such an arrange-
ment w'as perhaps Utopian, but in view of the enormous importance
of casting temperature it might profitably be appUed in the near
future. With such an arrangement 'it would be possible to abstract
the gases such as the authors had found were present before casting.
One other comment he would like to make, and that was that he
did not really understand why so many people were using this 88 : 10 : 2
alloy. He could not make out w'hat its advantages w^ere. Really
there were many other non-ferrous alloys which could be used, and
which for medium-sized castings were more easily cast and possessed
superior mechanical properties. He would like to add his congratula-
tions to the authors on the very painstaking and careful work that
they had done in connection with this very impoi-tant research.
* Time did uot permit Sir. Mun'ay to complete his remarks at the meeting. The con-
cluding portion of his contribution to the discussion will be found on p. 197. — Ed.
182 Discussion on Carpenter and E lam's Paper
I Dr. W. H. Hatfield (Sheffield) said that he also wished to con-
gratulate ]VIiss Elam and Professor Carpenter upon their most excellent
paper. After the dehghtful way in which Miss Elam gave the paper
it was very difficult, even if one so desired, to say anything severely
critical. However, he had mustered sufficient courage to say what
he really did think. Mr. Dewrance suggested that there should be
something to liberate the gas. Professor Edwards also desired to
abstract the gas. Now it seemed to him that this question of gas was
fimdamental in the production of sound castings, and the paper had
shown in a clear manner the effect which varying temperature had
upon the amoimt of gas that could be in solution. He thought
experience in ferrous metallm-gy would be very helpful in the bronze
industry ; now what was done in steel ? No attempt was made to
take the gases out. They were kept in. And it was a fact, proved
experimentally on several occasions, that if one took a piece of blown
steel and a piece of sound steel and abstracted the gases, one would
find that the gases in each case were similar as regards composition,
but that blown steel had less gas than the other. It seemed to him
that that was a fundamentally important fact. The gases were occluded
in the steel and following on that it seemed that the solution of the
difficulty would lie in adding a proportion of various elements which
would increase the holding power of the metal for gases. In the steel
that was accomplished by adding silicon and aluminium. The solu-
bihty of the hydrogen, nitrogen, and carbon monoxide in steel was
greatly increased by the addition of those elements, and he should
rather imagine that if the authors concentrated their attention in that
direction they might leadily find some means of adding to the per-
centage of elements to be discovered which would affect bronze in
the same way as those elements affected steel. Bearing on that, if
he might offer a word of criticism on the paper, it was this. In many
of the other metals which were used on a large scale it was necessary
to be extremely careful with regard to the analysis. The proportion
of other elements had a profound influence both on the physical and
chemical properties, and also upon the actual production of sound
articles. He thought it would be an added value to the paper to
liHve a complete detailed analysis of the alloys. It had occurred to
him on several occasions that non-ferrous people were not as particular
with regaid to the detailed composition of the materials as people had
U) be in ferrous metallurgy. That was all that he had to say, except
that he had enjoyed the paper immensely.
Mr. F. JoHNSOX, M.Sc. (Birmingham), said that he was afraid
that the time rationed for the discussion did not allow him to
traverse the whole of the ground that he wished to do, but he would
endeavour to deal as briefly as possible with those points which he
considered as of importance. On p. 156 and p. 160 the authors alluded
to the prevalent idea that ox\'gen gas played a considerable part
Discussion on Carpenter and Elam's Paper 183
in causing unsoundness. They were right in stating that there
was such a prevalent idea ; of course among practical men the idea
was prevalent, and amongst those " experts " to whom practical
men and others looked for guidance that idea was also prevalent.
But he did not think that one could consider, as Mr. Murray pointed
out, for a moment that oxj^gen qua oxygen was a gas susceptible of
occlusion in gun-metal. On p. 158 the authors stated that metal cooled
in a crucible was quite free from blowholes. In such a case as the
authors mentioned the process of solidification was considerably more
deliberate than the process of sohdification in the casting. He found
in making copper castings that unsoundness was a very great trouble,
and it might happen that copper which, if poured from the crucible,
would give a casting which would be merely spongy, would, if allowed
to remain and sohdify in the crucible, be perfectly sound. That had
been found by workers such as Dr. Percy and Hofman (in the United
States), and it was nothing new. The gases were allowed to escape by
this dehberate process of solidification more easily than they were
in the casting, in which they were generated at a faster rate than their
passage through the sohdifying metal could be effected. He would
like to ask the authors what they meant on p. 159 by the " nature "
of copper. They stated : " From the above observations it will be
evident that the natme of the copper and the various impurities in
it have Httle or only a minor influence." He understood that copper
had no allotropic transformations — that chemically pure copper would
always behave in the same way, and any di£Eerenc«s could therefore
be only due to impurities. The authors had mentioned the works
of Sieverts, and referred to the fact that he considered or had found
that carbon monoxide was insoluble in copper. He did not personally
agree with that conclusion, though he knew that some e\ddence in
support of it had been brought forward. But from practical observa-
tion he felt convinced that carbon monoxide was soluble in copper.
On p. 164: the authors referred to a black deposit on the tube. He
would ask them if they had considered the possibility of arsenic being
responsible for that black deposit, if they had analyzed the deposit,
and if they found more black deposit in some cases than in others ?
They also stated on p. 165 that a deposit on the tube was cupric oxide.
He would ask them k they had any evidence — if they had been able to
analyze this deposit and to prove that it was actually cupric oxide ? On
p. 165 also the authors gave a list of the densities of som.e castings.
In one case they gave the density as 9-00, which was higher than that
of copper itself. He would hke an explanation of that. They also
stated on p. 167 that zinc lessened the solubility of gases, but they gave
no evidence at all in proof of that. That might be right or it might
be wrong, but they gave no evidence whatever in order to prove their
statement. Also on p. 167 they gave the composition of gases in the
lower table, including carbon dioxide and carbon monoxide. The
carbon dioxide there was in excess of the carbon, monoxide, and in
184 Discussion on Carpenter and Elam's Paper
all other cases tlie carbon monoxide was in excess of the carbon dioxide.
He would like to ask whether those figures should not be transposed,
or whether they were actually correct. In all the other cases he
beheved carbon monoxide was shown to be in excess of the carbon
dioxide. Then with regard to the relationship between degree of
solubility and temperature, he would suggest that possibly some in-
formation might be gleaned by granulating the metal at various
temperatures, and in that way the gases might be retained so as to
indicate their solubility at those temperatures. The authors stated
that there was no free hydrogen in the copper to begin with. He
thought that hydrogen was the most soluble gas in copper. He would
also Uke to ask the authors if they had considered whether the water
vapour in the tube — upon dissociation — could be considered as a source
of the large volume of hydrogen when the evolved gases arc main-
tained at 1100° in contact with hot metal ? Professor Turner would
no doubt be able to speak on that point, as he had had some practical
experience with regard to these difficulties. Fox * had found that after
passing dry oxygen for 14 hours he had uot been able to remove all
the water vapour from the tube. With regard to conclusion 8 : "A
gas of approximately the same composition is found in both sound and
unsound sand-castings and in chill castings. There is not a constant
or sufficient difference in the volume of gas obtained from unsound
and sound castings to account for the presence of blowholes in the
one and their absence from the other." Dr. Hatfield had just pointed
out that in steel ^e could get in a sound casting more gas than in an
unsound casting, and he thought that Baker, in a Carnegie Kesearch
Memoir, f had shown that twice the amount of gas was present in a sound
as in an unsound steel. But there was a danger in taking the analogy,
because most elements, as the authors and others had shown, lessened
the solubility of gases in copper castings. In conclusion, there was
one matter to which he would like to refer. He had some photo-
graphs which he would like the authors to see of a bronze casting con-
taining oxide. It was the microstructure of a bronze casting of similar
composition to Admiralty gun-metal containing oxide, and it would
be seen that the typical copper-cuprous oxide eutectic formation
was shown in the photograph, and it would be seen from the etched
structure that the oxide was entrapped in the copper-rich dendrites.
The authors appeared not to have taken into consideration the reaction
between oxides of the metal and soluble gases, with the production
of a gas which was insoluble. They suggested a reaction between
gases only, but they did not appear to have taken into consideration
the possible and probable reaction between oxides and soluble gases.
Dr. W. RosENHAiN, F.R.S. (Member of Council), said that he
desired to associate himself with what had been said with regard to
* Thesis for M.Sc. degree, Massachusetts Institute of Technology.
t Carnegie Reaearch Memoir (Itoa and Steel Institute), 1909, vol. i. p. '219.
Discussion on Carpenter and Elam's Paper 185
the interest of having the opportunity of welcoming the first paper
from a lady research worker in the Institute. He took particular
interest in that, because he beUeved ]\Iiss Elam had obtained her
first experience of metallurgical research dming the year or so when
he had had the good fortune to count her among the staff of his
department at the National Physical Laboratory. The Institute was
fortunate, and Miss Elam was fortunate, in the fact that the research
upon which she was engaged or with which she had been associated
was one which it had been possible to publish. He would ask the
members to believe, and he thought it was only fair to say, that the
research was typical of a large amount of valuable work which was
being done by scientifically trained women at the present time in
metaUmgical research, only a great part was blocked from publication
for reasons with which everyone was acquainted. As regards the
subject-matter of the paper, he thought on reading it through one
could see at once that the practical conclusion was very definite, and
if mechanical tests of castings (not merely ingots), made by the
proper method, confirmed both with regard to strength and soundness
what those experimental results appeared to indicate so clearly, the
whole problem could be solved by temperature control. Now there
was a lesson there from ferrous metallurgy which might well be learnt
in that connection. He agreed with what Professor Edwards said,
that the difficulty arose in ordinary fovmdries from the fact that one
had to deal with large numbers of pots of metal which were small,
and therefore a large number required separate temperature measure-
ment, and they were liable to change rapidly in temperature. The
remedy for that seemed to him to lie in melting in much larger
quantities in an open-hearth furnace, taking off the metal in a ladle,
determining the temperature in the ladle, and then filhng mould after
mould much in the fashion in which it was done in the steel formdry.
With the quantity of production which was wanted in many cases it
would not seem that such a plan was so impracticable as it would
have appeared a few years ago. The electric furnace which Professor
Edwards suggested was, he thought, difficult of realization. He
had done a good deal of work on the electric furnace, and his con-
clusion was that for temperatures of 1100'* to 1200° no wire-woimd
resistance furnace was practicable ; there was not one material that
would stand as a commercial success for any time, working at that
temperature.
Professor Edwards asked whether tungsten wire could not be
used.
Dr. EosENHAiN repHed that the necessity of maintaining an
atmosphere of hydrogen was fatal, partly because the metal became
saturated with hydrogen and unsoimd castings resulted. To obtain
a vacuum liigh enough to allow tungsten to exist was impracticable
186 Discussion on Carpenter and Elam's Paper
on a large scale ; furtlier, tmigsten winding, once it had been used,
became so tender that the slightest touch shattered it, and its use
was, in his opinion, not a practical proposition at all. Graphite -
resistance furnaces, a type with which he had been concerned, and
other furnaces of that kind w^ere perhaps more feasible, but they
required comparatively heavy currents, and the use of those with a
trolley wire he thought would be very cumbersome work. The measure -
ment of temperature in the foimdiy was not so difficult as it appeared.
With regard to thermocouples, the chief difficulty lay in finding a
satisfactory sheath or protector, and for that purpose there were
three things which he would suggest as possible. The first was the
use of an iron sheath protected with an outer coating applied by a
spray process, such as the ordinary " aerograph " brush, consisting
of lime with some binding material, such as silicate of soda. He had
made actual trials, and they were using it every day with success,
though not on the scale of a large working foimdry. If those sheaths
were systematically recoated every time, or every other time, they
would last a very long time indeed. The second was the use of
graphite as a protector. That had the disadvantage of fragility, but
it lasted a very long time. The third thing he would suggest was a
sheath of carborundum tube. This was certainly very strong, not
quite so strong as an iron sheath, but it could be handled with fair
impunity, and did not introduce a serious amount of lag, because the
thermal conducti^ity was very good. He considered that if there
were a real need for it in the foundries something of that kind should
be made and should be very successful. Finally, there was the use
of the optical pyrometer, not attempting to apply it directly to the
surface of the metal at all, but immersing in the metal a long tube of
a refractory material closed at the lower end. There was a certain
amount of difficulty with the fume coming ofi in that case, but if the
tube was fairly long he thought it could be avoided.
Turning to the theoretical side of the paper, he had read the
explanation which the authors offered of the change in the gases, and
what happened when the metal was poured too hot, with a good deal
of scepticism. He knew it was a little ungracious to criticize a specula-
tion of that kind, but it struck him that it was not a good explanation
to suggest that a sudden drop of temperature would bring about an
equally sudden net total expansion of the gases. That could only
happen if there was a large liberation of energy which accompanied
that transformation, and he was inclined to think that thermo-dynamic
considerations woujd point the other way — that any change in the
gases or in the equilibrium of the gases which would be initiated by
a sudden drop of temperature would tend towards a net total con-
traction of volume rather than an expansion. The thermo-dynamic
considerations suggested that in most cases the reaction which would
takeVplace would be such as to diminish rather than to increase the
resulting total voliime. Finally he would aak one question as to the
Discussion on Carpenter and Elam's Paper 1S7
blue constituent of those alloys. He was not quite clear, from the
evidence given in the paper, as to the nature of this constituent, and
if the authors could supplement it in some way it would be extremely
helpful.
Mr. A, Cleghorn (Member of Council) said that he would Hke to
add his testimony to the value of pyrometry work in the brass foundry.
At Fairfield they had been so impressed, with the necessity of con-
trolling the temperature at which an alloy was pom-ed that about
seven years ago they entirely gave up the use of crucibles and crucible
furnaces in which to melt Admiralty and other bronzes and adopted
a reverberatory type of furnace.
These furnaces were specially constructed for the use of splint
coal, and were capable of melting 3 cwts. of metal in about thirty
minutes from charge to pour. The temperature of the molten metal
was recorded by a Baird & Tatlock electrical pyrometer, and when
it reached 1150° C. the metal was poured. Experience had proved
that at this temperature there was no difficulty in obtaining sound
and most satisfactory bronze castings.
After some experience with the pyrometer, the smelters also had
no difficulty in pouring the charges at the correct temperature, and
to aid them the furnace draught had been so adjusted that a temperature
of 1180° C. for Admiralty bronze could rarely be exceeded. It
was also found that other physical properties of the castings were
much improved, the ultimate tensile strength being increased by 2
to 1\ tons per sq. in. or 15 per cent, to 17 per cent., and other propei-ties
in proportion. With lower grade bronzes, containing a somewhat
larger proportion of zinc, the peicentage increase of strength was still
greater.
Mr. H. H. A. Greer (Glasgow) said he was glad that Dr. Carpenter
was going to make further investigations as to the fluxes. Not using
flux he believed had a great deal to do with the metal turning out
porous, more especially as he thought everybody must admit that
on almost eveay occasion new copper, tin, and zinc were not always
used, but, either for extra profit or for some other reason, a little piece
of old metal was inserted of the same quality ! It was well that some
further investigation as to what was the most useful flux might be
made. He was glad to hear Mr. Cleghorn speaking, because he was
not only a Member of Council of the Institute of Metals, but was also
President of the Institution of Engineers and Shipbuilders of Scotland.
He was one of the great practical engineers in Glasgow, and words
from a practical man were often worth many times as much as any
theoretical ideas. There was another point on which he would like
some investigation to be made. He had met two most clever chemists,
metallurgical men, in Scotland at their foimdries. One of them told
him that he would not allow phosphorus in any shape or form in his
188 Discussion on Carpenter and Elam's Paper
castiugs, and tlie other clieiiiist said that he Uked a bit of phosphorus.
He was up against " science " in this matter, and he had great difficulty
in huding out which was right and which was wrong. If the authors
would give a ruhng on that point, and say whether the use of phos-
phorus was sound or unsoimd, it would be useful. The paper was one
of those practical papers on which one always found there was a splendid
discussion whenever they were read before the Institute, and he warmly
welcomed it,
Mr. G. B. Brook (Sheffield) said that two things of importance
had been brought up that day, both intimately connected with external
and internal defects in cast ingots. In the paper before them they
had the question of evolution of gases, a matter that resulted in the
rejection of material, and was equally important with the external
surface defects mentioned by the author of the paper on die-casting.
Miss Elam stated that the presence of gas was almost inseparable
from copper alloys produced at high temperature. This the speaker
was able to confirm in part, but found that such unsomidness could
equally well be produced at a temperatme that was too low ; in other
words, in the case of cupro-nickel it was very marked at temperatm'es
above 1400° and below 1340°. AVith regard to temperature measme-
ments, it was gratifying to not« that more attention was being given
to this, in fact it was being demanded by the foundryman himself.
In this connection the speaker would draw attention to the very
mifortunately Hmited usefulness of the series of papers read at the
last March meeting on metal melting. Whilst a great deal of useful
data was brought forward, it was impossible to correlate the different
series of experiments in view of the almost entire absence of actual
casting temperatm'es. The President and Miss Elam in presenting
this paper estabhshed an example that might well be followed.
Obviously actual temperatures taken conjointly with the specific
heat of the alloy would enable actual comparisons to be made, whereas
the use ot the loose phrase " the alloy was melted in such and such a
time " was valueless. Some speakers in the discussion seemed to have
experienced considerable difficulty in finding a p}T.ometer suitable
to this class of work. An instrument made by the Cambridge Scientific
Instrument Co., consisting of a long silica tube which was plunged
into the molten metal, and to the head of which was fitted a metal
box containing the mirror and thermocouple gave satisfactory results
in the speaker's hands in the production of cupro-nickel. AVhilst
the cost of upkeep was considerable, it was more than counterbalanced
by the security ensured. After ths melter had once gained the ex-
perience of the correct temperature required, tests taken at random
over a period of two years showed that his judgment was very reliable.
He (Mx. Brook) would be glad to know what, in the authors' opinion,
was the condition of the sulphur in the molten metal, and further
would ask whether such gaseous evolution was common, also where
Discussion on Carpenter and Elam's Paper 180
coal or other gas^was used as a fuel, in wliicli tlie sulphur content was
obviously very much lower than in coke. The point raised by Professor
Edwards, suggesting that the time taken in skimming would result
in considerable loss of heat, was negatived by determinations made
by him (the speaker), in which it was shown that during a period of
five miimtes the temperature only fell ten to fifteen degrees, and this
working with comparatively small crucibles.
Dr. Hatfield's reference to the need for investigation into the
effect of impurities in non-ferrous alloys and estabhshing the same
liigli standard for materials as had been developed in the case of ferrous
alloys, was one, he was sure, that every member of the Institute would
liail with satisfaction.
f Professor Turner, who was in the Cliair, said that with reference
to the sections of alloys on the table, the authors had quite rightly
pointed out a fact which was not always recognized, viz. that when an
ingot was cut through or sawn through there were less holes visible
to the eye than there were present in the ingot originally. If one
took one of the blowholes and sawed it through, making a cut, say,
I in. in width, one cut a good piece out of the hole and one only saw
the sides of it ; these had been partly plastered up also by the rubbing
action of the saw and by the polishing action that was sometimes put
upon the ingot afterwards. If the polished surface was deeply etched,
very often holes would be seen quite plainly underneath, and the
method which Mr. Dewrance used, and which the authors had employed
also, of taking a small cut and not attempting to polish, was no doubt
a very much fairer way of getting a view of the interior state of the
metal. He was connected with a case only a few months ago where
samples were put upon the table in coiu't, sawn and polished specimens,
with the object of showing that the metal was perfectly sound, when,
as a matter of fact, it was full of blowholes. With regard to the kind
of blowholes worth)' of observation, some of them were globular and
had a clean and bright surface. Those had been mentioned in the
paper, and were no doubt due to the presence of non -oxidizing or
he might say, reducing gases. Then there were round globules which
were covered with red, purple, or l)lack stains, which were due to the
presence of sulphur in some cases, and probably to the prerence of
oxygen in others. Then there were clean internal spaces which were
not globular, but which were generally elongated and sometimes
pointed. Those were due to shrinkage, or to liquid contraction, and
they occurred either towards the centre of the ingot, or very often
towards the corners of a casting. Now all those were clean. Then
there were other holes which were filled with dirt, which dirt could be
recognized as consisting of various kinds. There was, for instance,
oxide of zinc ; there was foreign matter, such as sand, clinker, and
bits of coke. Lastly, there was a general porosity, small pinholes,
which might occur in different parts of the casting, and the cause of
190 Discussion on Carpenter and E lam's Paper
which was perhaps more obscure. It had to be recognized that there
were at least five, if not more, separate and distinct varieties of porosity,
and that the cure for one of them was not necessarily the cure for
another. The authors had done remarkably good work in showing the
effects of temperature when pouring. He had been connected with
the question of soUdity of castings and gases iif castings, and he could
say that he regarded the paper as the very best that he had seen, and
he congratulated the authors on what they had done. He might say
incidentally that some years ago he was consulted by a brass founder
who had a difficulty in connection with the want of solidity in his
castings, and he concluded that probably it was due to too high a
temperature, and suggested that the pot should be taken out of the
furnace and allowed to remain for some time till it had attained to
the right temperatme to allow the gas to escape. He saw nothing
of that man for nearly two years, and then he told him how successful
had been the work in his foundry and how grateful he was for that
simple piece of ad\dce. That was exactly on the same lines that
Professor Carpenter and Miss Elam had shown to be the case. He
merely knew it as the result of practical experience, and they had
shown it to be so from scientific observation. He had read the other
day in the " Journal of the Society of Chemical Industry," in the
last issue, an article in which the writer said that holding the mttal
when it was too hot, so as to allow it to cool down, did not always
answer ; apparently other conditions had to be taken into account
also. As to the great difficulty in connection with the collection
and analyses of the gases — when it was remembered that the total
quantity was usually somewhere in the neighbomhood of 5 c.c, and
sometimes much less than that, and out of that quantity one had to
allow for all the leaks and all the gases that were occhided on the
interior surface of the apparatus, and one had all the experimental
work to do in determining four or more different kinds of gases, it
would be seen how great was the care required, and that very special
skill was needed. When doing experiments of that kind with gases
in copper, he had found that if the tube had been carefully evacuated at
a high temperature, and allowed to cool, and then had been re-heated
and evacuated again, the empty apparatus gave nearly a cubic centi-
metre of gas, and if the experiment was repeated a third time tliey
still got a trace of gas, but after that the tube gave practically no
gas whatever. He was doubtful about using a silica tube, because,
although he had no evidence for it, he had read that at and above
1200° a silica tube allowed hydrogen to pass. It was doubtful as
to the souice from whence that hydrogen came — whether it was
originally present in the silica, or whether it came through by some
system of diffusion of the moisture in the air. It might be that silica
(lid not allow hydrogen to pass, but at any rate he used a porcelain
tube instead of a silica tube for high temperatures, because he had
got the information somewhere. He felt that the question of gases
Authors' Reply to Discussion 101
in alloys would have to be reinvestigated. He did not say that the
authors were wrong. The conclusions might be wrong, or might be
right. But the authors themselves had shown how complex the
question was, and that there were other questions still unsettled, and
he thought that part of the research must be regarded as merely a
step in the whole investigation. From the practical point of view
the paper was admirable, and he was quite sure that the members
desired to record their very sincere thanks to Professor Carpenter
and Miss Elam for bringing before them a paper which had evoked
so much interest. Miss Elam had many questions to reply to, even
if she only touched on half those which had been asked. Probably
she would prefer to reply to some of them more in detail afterwards.
Miss Elam, in reply, said that Mr. Dewrance evidently thought
that it would be desirable if something could be added to the alloy,
so that the safety range could be increased. There were considerable
disadvantages in adding other things to the copper, apart from the
extra time and trouble involved. The trouble of adding such a sub-
stance to the copper was as great as taking the temperature of the metal.
In one experiment ^ per cent, of a 10 per cent, phosphor-copper alloy
was added before the zinc and tin, but this did not improve the castings,
which were still unsound when poured at a high temperature.
Mr. Thornton Murray suggested that they had not accounted for
the possibility of failure through shrinkage. She did not think that
the flaws in the casting shown could possibly be caused by shrinkage.
Considering it had risen in the mould quite an inch, it must have been
due to just the ppposite cause. The authors did not consider that
physical (mechanical) tests entered into the question regarded from
their point of \dew. They wished to clear up the question of the
blowholes, and whether the metal was any better from a mechanical
point of view had no direct connection with the research. (It followed,
necessarily, that the sounder the metal the better the mechanical
properties.)
They i;sed a silica protector for the thermocouple. It lasted for
several heats, but slagged very much with the copper oxide and broke
up in the end. It was quite possible, if it were coated with somethiig
to protect it, that it would do very well. Radiation pyrometers wore
used in the foundry, but the objection to them was that the actual
temperature of the metal itself was not registered ; it was merely
the temperature of the skin which was measured as a rule, and this was
a good deal lower than that of the metal. With regard to the nature
of the copper, she really meant the different brands of copper — Rio
Tinto, Selected, Cathode, &c. The latter was used as it came from
the cathodes. Practically no advantage was found in using any one
sort of copper more than another, so that they did not think there
was any need to go into the actual composition of the copper. It
may have had some effect, but the general results were the same.
192 Authors' Reply to Discussion
Zinc, she thoiight, must lower the sohihility of the gases. In the
first place, the analysis of the gas from an alloy containing zinc had
a good deal less sulphur dioxide and hydrogen sulphide in it than
the gas from pure copper and from a copper-tin alloy. The zinc no
doubt interfered with the gases in collecting them, so that the total
volume in the metal was not really measured. At the same time
the difference in quantity from the two sorts of metal {i.e. that with
zinc and that without) was quite sufficient to warrant the conclusion
that the zinc does lower the solubility of these gases. Dr. Rosenhain
thought that their conclusion with regard to the volume change arising
from the dropping of the temperature due to pouring could not be
correct. They did not consider that the gases merely expanded, but
that the equilibrium of the gases must be altered, especially by such
a sudden change of temperature, and it was quite possible they might
react and so account for the larger volume. It was not actually an
expansion of the gases as they stood. Personally, she did not feel
any doubt that the dark grey inclusions were oxides. She managed to
reproduce them in other alloys where there was no doubt as to their
identity.
Miss Elam said that Mr. Brook had mentioned the fact that copper-
nickel was imsoimd above and below a critical temperature. That
was sometimes so in this case. But although the imsoundness was
very marked when it was poiired at much too high a t€mperature, it
was not by any means constant when poured too low. There was
one casting poured at about 1050° C. which was full of holes, but these
were probably due to contraction. She did not think it was due to
gas in that case at all. As to the presence of sulphur in the copper-
there was sulphur in the electrolytic copper used. Wlien the metal
was heated in vacuo the sulphur volatihzed in the tube, and there was
quite a distinct deposit even from the cathode copper. With regard
to silica being permeable to hydrogen at liigh temperatures, the fact
that in several of the analy.ses given there was no hydrogen at all
disproved that statement.
There was one point which the speakers had misunderstood, namely,
they thought that the gas escaped between the first and second casts,
and that accoimted for unsoundness when pouring was done at too
high a temperature, and .soundness when done at the con-ect tempera-
tiu"e. The authors did not agree with that statement at all. There
was nothing to prove it. The volumes of gases obtained from sound
and unsound metal agreed so nearly that she did not think it could
be concluded that the gas escaped on coohng. In addition to this,
there was the difficulty that was experienced in extracting it even
in vactio ; sometimes the metal had to be heated three or four times
before the gas came off, and at ordinary temperatiires it would be
considerably more difficult for it to escape.
In conclusion, the authors wished to thank all those who took part in
the discussion for their interest and friendly criticism of the paper.
Commttnications on Carpenter and Elam's Paper 193
COMMUNICATIONS.
Mr. J. L. Haughton, M.Sc. (Teddington), wrote that lie wished
to make a few remarks on the most interesting and valuable paper
which had been presented to the Institute by Professor Carpenter and
Miss Elam. The first point concerned the composition of the gases.
The authors had found that there was not a sufficient difference in the
composition and volume of the gases obtained from the sound and
unsound castings to account for the difference in quality in the metal.
A very similar conclusion had been arrived at by J. Cartland,* working
in Professor Turner's laboratory in 1911, on sound and unsound castings
of brass. In this case the brass was cast in dressed and undressed
moulds, and the gas evolved on remelting was analyzed. The average
analysis of the gas was :
Par Ceut.
Carbon dioxide 3-6
Carbon monoxide ...... 27-0
Hydrogen ....... 59-0
Marsb gas ....... 5-6
Oxygen ........ nil
Nitrogen ........ 4'S
It would be seen that the above was very similar to the analysis
given in the last column of the table on p. 168.
He (Mr. Haughton) was particularly interested in the blue con-
stituents referred to by the authors. He had noticed these constituents
on many occasions in gun-metals containing lead. On the other
hand, he had also seen a similar blue constituent in an alloy containing
approximately 60 per cent, copper, 40 per cent, zinc, which w^as free
from tin, and this constituent was completely unattacked by acid
ferric chloride, and therefore, according to the criterion given by the
authors on p. 160, was not zinc oxide. He considered that some more
work was necessary on these interesting constituents before it was
possible definitely to state that they were the oxides of tin and zinc,
though he agreed with the authors that this was the probable
explanation.
With reference to the question of temperatiue control, which was
largely referred to in the verbal discussion on the paper, it appeared
to him that this was a case pre-eminently suitable for the Rudge-
Whitworth type of pyrometer, which worked on the principle of a " go-
and-not-go " gauge. He had no experience of the instrument, but if,
as the makers claimed, it would read to 25° C, it should be quite
suitable for the purpose of keeping the casting temperature of Admiralty
bronze well within the comparatively wide range specified by the
authors.
• J. Cartland, Journal oj the. Institute of Metals, No. 1, 1912, vol. vi. p. 268.
VOL. XIX. O
194 Communications on Carpenter and E lam's Paper
Mr. F. Johnson, M.Sc. (Birmingham), wrote, in continuation of
his remarks at the meeting, that it had occurred to him that the
greater difficulties associated with producing sound castings of copper
as compared with castings of bronze might be attributable to the
order of freezing of oxide.
In the case of copper to which no deoxidizer had been added, the
cuprous oxide was the constituent of the copper-cuprous oxide eutectic.
In the course of freezing the mother liquor would become progressively
richer in oxide, and probably also in gases. At a certain stage in the
freezing process, the degree of concentration of oxide and gases in the
mother liquor became such that a reaction took place, with the forma-
tion of insoluble gases which, in endeavouring to escape from the partly
solidified mass, produced cavities or even projected metal from the
castings with eruptive violence. He had never known this to happen
in the case of bronze castings to so marked an extent. He suggested
that, in the case of bronze, any dissolved oxide would have a higher
freezing point than the tin-rich mother Hquor, and the dissolved gases
in the latter would therefore have no oxide with which to react after
a certain stage in the solidification process. This did not mean that
no reaction between oxide and dissolved gases could occur, but that
such reaction would be confined more to the earlier stages of the
solidification, when the free escape of the products of the reaction,
viz. insoluble gases, could be the more readily effected.
He wished to make reference to the title of the paper, which read
with some degree of ambiguity. Instead of " An Investigation on
Unsound Castings of Admiralty Bronze (88 : 10 : 2) : Its Cause and
the Remedy," would it not be better that it should read as follows :
" An Investigation on Unsoundness in Castings of Admiralty Bronze
(88 : 10 : 2) : Its Cause and the Remedy " ?
In conclusion, he (Mr. Johnson) felt that the last word had yet
to be said regarding the remedy for unsoundness. It appeared to him
that much was to be expected of improved means of deoxidizing the
metal, or of melting under conditions where oxidation was minimized,
if not eliminated.
Dr. Percy Longmuir (Shefl&eld) congratulated the authors on
their research, and especially on the conclusion they had reached,
viz. " that the casting temperature has the greatest efiect on the
quaUties of the material."
He (Dr. Longmuir) had done a httle work in this direction, and
some twenty years ago practical experience convinced him that the
real problem lay in the effect of varying casting temperature on
mechanical properties rather than in the direction of unsoundness.
In a paper read before and published by the Sheffield Society of En-
gineers and Metallurgists (March 12, 1900) he stated, in referring to
the 88 : 10 : 2 alloy : " The sharp graduations in the section of metal,
combined with the narrow range of casting temperature, necessitate
Communications on Carpenter and Elam's Paper 195
sp ecial care in the melting and casting of this alloy, the more so if
the castings are desired to withstand the high pressures of present-
day marine engineering."
In this paper, " Brasses and Bronzes," tensile tests from bars all
poured from one crucible at time intervals of two minutes were quoted
as follows :
No.
1
Maximum Stress. i ^'^"f^*C °°
Tons per ScMa. | |Jtnt
1
2
3
132 1 50 ;
170 ; 11-0 j
13-0 8-0
The results of a more systematic investigation were to be found
under the heading of " The Influence of varying Casting Temperature
on the Properties of Alloys," in the Journal of the Iron and Steel
Institute, No. I., 1903. A further general summary of work in this
direction was included in " General Foundry Practice," by McWilliam
and Longmuir, first published in 1907.
From work done and results obtained, he (Dr. Longmuir) would
emphasize the fact that unsoundness due to varying casting tempera-
ture was of secondary moment to that of the efEect on other properties.
This could be readily proved in the case of any non-ferrous alloy, and
especially in the case of the standard 88 : 10 : 2 by heating a crucible
to a very high temperature, immediately pouring one bar and then
successive bars at stated intervals. It was, of course, essential that
the only variable should be that of temperature. If this care were
taken it would be found that whilst the bars were sound they would
present a distinct variation in tensile properties. The results would
also confirm, within the limits of soundness, the terms "hot," " fair,"
and " cold " described in the 1903 paper already mentioned.
The authors gave as a suitable casting temperature 1200° C, and a
range of about 150° C. within which sound castings could be obtained,
but in conclusion 12 the latter was narrowed to 120° C, viz. 1270°
to 1150° C. Did that range apply equally to a five-ton casting and
to one weighing one ounce ? Apart from mere weight, contour,
change of section, and other vital features had a very determining
efEect on suitable temperature if the best and safest type of casting
were to be obtained. It was indeed most difiicult to give a range to
cover every type of casting made, and it ^\'Ould be well if the authors
would check the range given over a variety of forms before finally
issuing it to practical foimders.
The authors were to be congratulated on the evidence they had
presented, but he (Dr. Longmuir) was sure that they would be the
first to admit that this evidence required much further amplification,
196 Communications en Carpenter and Elam's Paper
and lie trusted that they would continue the work so well begun, espe-
cially in the direction of physical variation within the limits of perfect
solidity,
Mr. W. E. W. MiLLiNGTON (Manchester) wote that it was rather
unfortunate that the authors in their paper did not clearly specify
what they meant by the term " unsoimd " as applied to castings.
If castings which satisfied the specified tensile and hydraulic tests
were considered " sound," then he (the writer) maintained that there
was very little difiiculty in obtaining sound castings by anyone at all
familiar with this alloy. If, on the other hand, the authors referred
to sound castings as being only those which did not show anywhere
any microscopical defects, he maintained that it was practically
impossible to obtain such castings in 88 : 10 : 2, no matter what the
pouring temperature of the metal might be.
There was no doubt that, as the authors stated, difficulties still
existed in this country in satisfactorily casting 88 : 10 : 2, but in his
opinion this was almost entirely due to ignorance on the part of the
particular founders, and to the fact that the Admiralty test specifica-
tion of 14 tons per square inch ultimate strength, and 7| per cent,
elongation in 2 in., was too low. If this material were properly cast,
a very large margin above these figures could be obtained, or, in other
words, the specification could be satisfied by comparatively poor
material. The result was that since the tests could be obtained with
little more effort than simply melting the metals and pouring into a
hole in the sand, many foundries were content to work on the " hit
and miss " principle. In the writer's opinion, if the specification
called for 15 to 16 tons per square inch ultimate strength and 15 per
cent, elongation — a test which could still be comparatively easily
obtained — founders would be compelled to deal with the alloy in a
more scientific manner, since many of the present methods would not
produce the required material, and very much better work would be
produced in consequence.
On p. 158 the authors appeared to state very definitely that metal
allowed to cool in the crucible was quite free from porosity. This
was by no means his experience, as he had repeatedly found that
metal so treated showed porosity, and sometimes to a very consider-
able extent.
The portion of the paper describing the collection of and the compo-
sition of the gases was very interesting, but, personally, he thought
this had very little connection with the cause and remedy of porosity
in 88 : 10 : 2 castings. Paragraph 8 of the summary at the end of the
paper almost suggested that the authors were of the same opinion.
On p. 172 it was stated that the problem " is essentially one of
temperature control and nothing else." He (Mr. Millington) begged
to differ from the authors upon this, as his own practical experience
>showed that there were many other factors which must be taken into
Communications on Carpenter and Elam's Paper 197
account if satisfactory 88 : 10 : 2 castings were to be obtained. For
example, rate of melting, metliod of melting, method of moulding,
method of running, rate of pouring, and size of casting were all factors
whicb bad a great influence upon the resulting casting. This would
appear to be borne out by the poor results obtained in some foundries,
since temperature alone would hardly account for the troubles, seeing
that there was so large a range as 150° C. between the upper and lower
limits of temperature of pouring as suggested by the authors.
In conclusion, he would like to thank the authors for again bringing
to the notice of members this question of unsatisfactory 88 : 10 : 2
castings, but would suggest that much more investigational work
might be carried out on the subject with great advantage. Again, he
would suggest that if the specification tests were increased, better
work would result.
]VIr. M. Thornton Murray, M.Sc. (Birmingham), wrote, in con-
tinuation of his remarks at the meeting on the question of gases in the
alloy under discussion, that if by any chance the hydrogen were in
solution in the metal all the time, and if it were removed only when
certain conditions of pressure and equilibrium were established in
contact with the metalHc surface, the question of the absorption and
evolution of the gases might assume a somewhat different complexion
from that viewed by the authors. That idea the authors might
be able from their experience effectively to nullify. Could oxides
exist in contact with hydrogen, for example ? With regard to the com-
parison between sand and chill-castings. Figs. 3 and 4 (Plate VII.)
showed practically negligible blowholes, or rather Fig. 4 did. His own
experience had been that it was often very difficult to identify blow-
holes under the microscope, as they were frequently filled with polishing
material, and had their typical bright surfaces dulled or blackened.
Touching the method of preparation adopted for tracing the rough
specimens, he had found similar methods useful, but only for detecting
relatively large blowholes. He preferred for a rough test the lens
examination of a fractured surface. In view of the great differences
in structure between the chill-cast and sand-cast specimen, he was
somewhat surprised that that line of research was not followed a Uttle
further, as, although the gaseous content showed little constancy
of difference upon evacuation, the mere fact that the bubbles were
so small in the chill-castings had immense practical potentialities.
It might be remembered, too, that in a complicated casting, even in
sand, the smaller sections were in effect often chilled, even when
artificial chills were not used, while the larger sections were cooled
slowly. Would not this tend to restrict the porosity to the larger
bodies of metal ? Of course shrinkage cavities would occur in the
latter also, and care was needed to be exercised to distinguish one from
the other. Mention was made of reagents (probably deoxidizers)
which by keeping the metal free from oxides, and therefore more fluid,
198 Communications on Carpenter and Elanis Paper
probably indirectly assisted in tlie expulsion of gas bubbles. He
hoped to bear more of tbe tests wbich the authors had in hand. He
should like to conclude by saying that he hoped that none of the
remarks that he had made either at the meeting or in the present com-
munication would be taken as a criticism of such a very admirable
and useful paper, but rather as an incentive to the authors to carry
out their work in a further direction, and if possible give more help
to foimdrymen than they had already done.
Mr. W. B. Parker (Rugby) wrote that Professor Carpenter and
Miss Elam were deserving of congratulation upon the ruthlessly
scientific and very successful manner in which they had tracked down
and proved one important cause of unsoundness in castings (ingots)
of 88 : 10 : 2 bronze. The metallography of the research had been
very well done, and the information thus obtained would prove useful
in everyday works practice, not only with Admiralty gun-metal,
but also with many other copper-zinc alloys.
One feature respecting foundry troubles which was frequently
observed was that some types of them seemed fashionable at certain
foundries but out of fashion at others. In a recently observed instance
one foundry experienced trouble with Admiralty bronze (88:10:2),
but was going along beautifully with Admiralty phosphor-bronze
bearing alloy, whilst at the other foundry the case was exactly the
reverse. By exchange of confidence and experience both ultimately
did well in both these alloys. It often appeared that the one thing
requisite for foimdry efl&ciency on a national scale was more latitude
for frank interchange of opinions and experiences. In a large number
of cases an empirical solution of a problem had been arrived at by
some one.
When papers of the present practical type were presented, would
it not be advantageous to form a joint meeting with, say, the British
Foundrymen's Association in order to get practical foundry views ?
For example, many foundrymen would not follow the method employed
by the authors for mixing their metal ; a more usual works method
was to heat the copper until just on the melt, and then add the tin,
which, by reason of its alloying with the copper, made the whole charge
go rapidly liquid without any chance of overheating the charge.
Then, in a few minutes, the metal was ready to draw, and the zinc was,
more often than not, added to the melt after it was lifted from the fire
— thus avoiding the loss of zinc, and making it much easier to control
the condition of the metal. The actual casting temperatuje used was
mainly dependent upon the type of the casting to be poured — usually
it was round about 1000° C, but no hard-and-fast value would stand
a chance in general foundry practice.
The practice of super-heating the alloyed metal (resorted to by
the authors for purely experimental reasons) was never used in any
foundry working to " guarantees " and for profits. Although for
Communications on Carpenter and Elam's Paper 199
years connected with everyday production of 88 : 10 : 2 bronze castings,
he (IVIr. Parker) could not recaU a really serious instance, or series of
important instances, of unsound castings in his own practice with this
particular mixture.
The above statement was certainly not made as a personal boast —
no one connected with such an intricate business as engineering brass
foundry work should indulge in boasts ; but nevertheless it was a fact
that porous gim-metal castings had been exceptional to the extent
that no demand for a special research Hke the one under discussion
had arisen, hence, although occasional porous castings had been in-
vestigated microscopically and chemically, no examination of the
gases they contained had been attempted, and he therefore had no
data to add to this portion of the research.
Taking the authors' comments on p. 156 relative to the "jdifficulties "
which " stiU exist in the foundries in this country," together with the
content of the paragraphs headed " Practical Considerations " and
" Summary and Conclusion " (pp. 171 and 174), one was forced to infer
that the authors themselves had deduced that the unsoundness of
88 : 10 : 2 bronze castings had everywhere arisen mainly from sheer
carelessness in the melting and casting of the alloy, the residuum
of trouble being due to two other faults :
(1) Badly made moulds.
(2) Badly designed castings.
Many foundrymen would refute this deduction, and could do so
with justice. It was evident to managers and metallurgists of foundries
that the authors were under a misapprehension, especially with regard
to the methods of melting and casting most generally followed in British
foundries. This was regrettable, because, apart from the data upon
the composition of the gases, the above inference clearly represents
the essence of the paper. There was a good percentage of foundries
where constant and proper care was exercised in these matters, and
the percentage of gun -metal castings rejected for purely foundry
faults was usually below 3 per cent, of the total output. Whenever
employers equipped their foundries in a reasonable manner and en-
couraged their employees to become not merely efficient in an em-
pirical sense, but also scientifically, the almost entire disappearance
of unsound castings in standard Unes of production was ensured.
Probably one of the best aids to this desideratum was the installation
and liberal maintenance of a properly equipped and staffed metal-
Im'gical laboratory.
The authors' plea (pp. 173-175) for the provision and use of pyro-
meters in every brass foundry should receive strong support. These
instruments were very valuable for teaching as well as maintaining
efficiency in production. In the production of guji-metal castings,
and other alloys possessing similarly reasonable ranges of casting
temperatuje, the men soon passed the stage at which it was necessary .
to test pyrometrically every pot of metal made, and consequently
200 Communications on Carpenter and ElamJs Paper
there was no sensible " delay " in the run of production of the less
important part of such work. All important work should be tested.
For control of such mixtures as 88 : 10 : 2 gim-metal the writer used
a Cambridge Scientific Instrument Co.'s platinum-platinum-rhodium
thermocouple pyrometer, the miUivoltmeter indicator for which was
graduated in 10° divisions from 0° C. to 1400° C. This instrument was
also used for so-called manganese bronzes and " high manganese "
brasses.
For aluminium alloys a second instrument of the same type was
provided, ha\'ing a range from 200° to 1400° C. For phosphor-bronze,
nickel castings, and high conductivity (100 per cent, pure) copper
castings a Cambridge Fery total radiation pyrometer (thermo-electric
type) was used. This instrument worked with an indicator which
possessed two temperature scales, viz. 600° to 1400° C, reading to
10° C, and 1200° C. to 2500° C. graduated in 20° divisions between
1200° and 1900° C, and in 10° C. from 1900° C. to 2500° C. One
marked advantage of the last-named type of pyrometer was that it could
be rehed upon as a standard for rapidly checking the accuracy of the
ordinary thermocouple types which were in constant use at the top half
of their temperature scales.
With reference to the fourth method of obtaining soundness (p. 174),
" chemical in character," the action of some of the substances used in
this method had been discussed with Mr. J. Dewrance and ]^Iiss C. F.
Elam at an early stage of the present research, and it was understood
that a second research was to record experiments with them, and
especially with the reagent " Boroflux," which had been supplied to
them by Messrs. The British Thomson-Houston Co., Ltd., Rugby,
who were the manufacturers of this proprietary article. It was hoped
that it was not spoiUng the second paper to state a resume of the
writer's practical experiences with some of the commonest of these
" reagents," all of which had received extensive study and trial in
the chemical department and foundry of the above firm.
Magnesium (used both as metallic magnesium and copper-magnesium
alloy). — This method was efl&cacious as far as mere production of sound-
ness was concerned, but it was not suitable for high conductivity
copper castings. It was therefore abandoned for this purpose as
far back as 1904. This reagent was still in use for pure nickel castings
and high percentage nickel alloys.
Phosphorus (used as phosphor-copper). — This reagent was given a
very extensive large scale trial in connection with H.C. copper
castings, but was never really satisfactory, and upon account of its
erratic action it was abandoned. For production of phosphor-bronzes
{i.e. true tin-copper alloys) its use and also that of phosphor-tin was
still continued with satisfactory results.
Its application to zinc-containing alloys — gun-metal and such like
— proved rarely of any real value, or, rather, the improvements, if any,
could never be definitely ascribed to its use.
Communications on Carpenter and Elam's Paper 2ul
Aluminium (used as metallic aluminium ; also as 50 : 50 copper
aluminium). — This reagent received trial in the production of H.C.
copper castings, but for this purpose was found unsuitable and was
abandoned. It was very useful in certain high-tensile brasses ; most
of such alloys contained aluminium.
Vanadium (used as cupro -vanadium alloy). — ^As at present put on
the market, this deoxidizer was " a bit of a fraud." It was always
contaminated with aluminium — sometimes containing as much as
7 per cent, of this element. All the good efiects ascribed to the use
of cupro-vanadium were really due to the aluminium which it contained.
When the manufacturers could regularly produce pure cupro-vanadium
in a form which was soluble in copper, its study would be resumed.
Calcium (used as metallic calcium). — A very considerable amount of
large-scale work was conducted with this element, especially in connec-
tion with the production of pure nickel castings and high melting nickel
alloys, but it was abandoned. The metallurgical behaviour of this
element was interesting, and a paper upon the subject would be worth
attention.
Silicon (used as copper-silicon ; various percentages of siHcon). —
After some six months' work with this element it was abandoned.
It never proved of any use for producing sound 100 per cent, pure H.C.
copper castings. It was also tried in copper alloys with tin and zinc
(singly and together), and although if used in moderation it did no
harm, yet its continued use did not appear to be warranted by the
results obtained.
Manganese (used as metalUc manganese and copper-manganese). —
This well-known deoxidizer had been extensively used, and was of
course well known to be suitable for many brass-foundry alloys, but it
was quite useless for the production of pure H.C. copper castings,
Boron.—Hhis element, a comparatively new addition to the list
of reagents or deoxidizers, was the only one which had proved satis-
factory for the everyday production of sound 100 per cent, pme high
conductivity copper castings of all sizes and types. This characteristic
was largely due to the fact that it did not unite with copper. Its value
for this purpose was discovered by Dr. E. Weintraub about 1907,
while employed in the research laboratories of Messrs. The General
Electric Company, West Lynn, Mass., U.S.A. Its use for the above
purpose had been patented in nearly all countries, and the British
patent rights were held by Messrs. The British Thomson-Houston Co.,
Ltd., Kugby.
In the foundry of the last-named firm extensive and successful
apphcation had been made of boron in connection with the production of
soimd 100 per cent, pure copper castings for electrical purposes, and
the process was standardized for everyday foundry products. As
he had explained on another occasion to Mr. Dewrance and Miss
Elam, boron could be applied to the production of gun-metal castings,
tin bronzes, and ordinary brass mixtures, but its everyday use in
202 Commimications on Carpenter and Elam's Pape^
such mixtures was usually not urged, because it was evident thai
in such alloys the other ingredients (tin, lead, zinc, aluminium
manganese, &c.) rendered its use more or less imnecessary. Prool
of this was readily deduced from the authors' remarks on p. 159
which the writer could fully endorse, namely : " Zinc and tin act as
deoxidizing agents to copper in that they reduce the cuprous oxide."
In fact, some fifteen years ago this was proved in experiments with
small additions of tin and zinc to copper ; but both elements had a
very bad efiect upon the conductivity of copper and proved valueless
for the specific object then in \'iew. On the other hand, when a case
arose where it was of extreme importance to avoid all possible chances
of unsoundness and to ensure absence of oxide films (of tin, zinc, copper,
&c.), boron had a very specific claim to be used, and had proved of
real value. This was especially the case if any suspicions existed with
respect to the quahty of the copper which must be used. In all such
cases the copper should be treated with boron prior to the addition of
the alloying elements — tin, zinc, &c. For this purpose it was melted
and then superheated up to between 1300° and 1500° C, and while
still at that temperature the required boroflux was added and mixed
in well by means of a graphite stirrer. The metal was then allowed
to cool somewhat, skimmed, and the zinc added, then the tin, or vice
versa, and the alloy cast with the usual precautions. It should be
noticed that only the copper was superheated — not the alloy. By the
" boronizing " process the oxygen which dissolved in the unalloyed
copper during its melting was eUminated, and any dross was also got
rid of, because the boron trioxide (BjOj) produced formed an ideal
flux for all such dirt and oxides. The boroflux now in use consisted
of boron carbide. This was more readily prepared and handled than
the earlier forms (suboxide BgO) mentioned in the literature referred
to below,* but it was used in exactly the same manner. Of course
in the case of all zinc alloys (brass, gun -metal, (fee), some zinc oxide
was imavoidably produced upon the surface of the molten metal
immediately the " zincing " was commenced, and even with a " boron-
ized " alloy it was highly desirable to avoid undue agitation of the
metal. Careful skimming prior to casting was as essential as ever.
In fact, " clean and steady " pouring was always desirable in foundry
work — ^its attainment easily distinguished a skilled and properly trained
caster from an unskilled one.
With reference to the appearance of the interiors of blowholes in
gun-metal — whilst it was true that these were most frequently bright
and free from coloured oxide films, yet in actual castings they were
sometimes tinted. It depended upon whether air had gained access
to them while still hot — this it sometimes did, owing to the presence
of very fine intercrystalline cracks produced by shrinkage phenomena.
• TraruaciioM of ths American Eiectrocliemiail Society, 1909, 16, p. 165; also 1910, 18,
p. 207; Chvnical .New*, .^ept. 29, 1911, p. 157; Thorpe'g Dictionary of Apjdied Chemistry,
vol. i. p. 498.
Communications on Carpenter and Elam's Paper 203
The whole of foundry work was inextricably wrapped up with the
question of " shape " — castings were quite frequently awkward to
mould, pour, feed, and cool, and then shrinkage cracks, fissures, and
cavities were to be expected and were often produced. Shrinkage
fissures and cavities were far too frequently confused with true
" blowholes " (gas-holes).
It was almost certain that the reason why the lumps of gun-metal
(produced when the authors allowed the metal to cool and solidify
undisturbed in the crucible) were invariably sound, whereas the sand-
and chill-cast ingots were not sound, had nothing to do with their mere
freedom from agitation, nor to initial temperatures of melting, nor to
absence of sudden variation in rate of cooUng consequent upon the fact
that they were not poured, but was due to (1) difference in shape, and
especially to (2) the perfectly natural feed of the metal as it cooled in the
simultaneously cooling crucible in contradistinction to the more or less
forced and imperfect feed which naturally always resulted from the
comparatively rapid simultaneous cooHng and solidification of ingots
at the sides, bottom, and top. The writer hoped to go further into this
point at a later date, since he believed that he had observed phenomena
which proved the truth of the above comments. In the case of the
unsound (pure) copper castings {i.e. those made without boron or any
other deoxidizer), the blowholes were usually more or less tinted.
There was a good basis for the general opinion that the presence of
oxygen accounted for most of the trouble of blowholes in copper,
and there was a distinct need to distinguish between pure metal castings
of single high melting elements like copper, nickel, or cobalt, and alloyed
metal castings like gun-metal, brass, &c. Tliis point was not suffi-
ciently emphasized by the authors on p. 160, hues 17-20.
The authors omitted to give the analysis of the Rio Tinto ingot
copper which yielded the gases detailed on p. 167, neither did they
mention any precautions taken to ensure that prior to combustion
the samples used were perfectly clean (free from surface dust, oil, and
all organic matters).
Did they find that the total oxygen in the gases tallied with the
total oxygen found by the ordinary process of determination of oxygen
in the ingot copper, and did the latter tally with the percentage of
cuprous oxide, determined by a microscopic examination of the ingot
copper ? If so, it was certain that neither the carbon monoxide nor
carbon dioxide that they report could have existed as such in the
ingot, and consequently they must have resulted from combustion of
ordinary organic contaminations or volatilized grease, which possibly
was creeping in from the ground-glass joint. Without wishing to be
super-critical, the writer considered that the utility of the paper to
foundrymen would be improved by addition of tensile tests for the
sound and unsoimd portions of each of the ingots investigated.
Its purely scientific value would be enhanced further by some-
practical account of the apparatus and methods used for the gas
204 Communications on Carpenter and E lam's Pape
analysis. The results of the latter formed so important a featur
of the report (in fact they constituted the main witnesses in the case
that the whole paper must stand or fall according to their real value— j
hence more details concerning them were very requisite.
AVith regard to the references on p. 161, the authors omitted to men
tion that Marcel Guichard not only employed a vacuum but also iodine
and oxygen in his research, and converted his copper into iodide oi
oxide, thereby driving ofi the dissolved gases it contained. He found
that 100 grms. of copper gave 22 to 30 c.c. of gas by this method.
The paper was of very great interest, and was sure to prove oi
practical value, and its perusal made one look forward to the second
part dealing with deoxidizers.
Mr. H. S. Peimrose (Braintree) wrote that the authors had
approached a complex investigation in an admirable manner, but it
was regrettable that definite values were not attained in the gas analyses.
This was always the disadvantage of using small amounts of metal,
and the possibility of a leakage accounting for the unexpected elements
found in their results.
After stating the object with which they had undertaken the
research, it was disappointing to find at the conclusion of the paper
that the authors had, not estabUshed any case for such a practical
discovery. The practical considerations undoubtedly summarized
the general concensus of opinion as to the best method of producing
ingots or small test-bars for inspection, but it was not proved, that their
ingenious method of finding the approximate amount and composition
of the gases contained in or given ofi by certain grades of gun-metal,
melted in too small quantities for practical purposes, had caused them
to arrive at the same conclusions as the American Bureau of Standards.
The claim made by the authors — that the problem of producing
sound castings (not ingots) was essentially one of temperature control
and nothing else^ — was not justified, because every practical founder
knew that many other causes might contribute to the defect of un-
soundness, such as a badly designed pattern, dampness in the mould,
bad venting, splashing of metal in the runner, &c. They might with
advantage have taken into full consideration the exact conditions of
the furnace working, either in the coke or gas furnaces used, since the
furnace temperature and speed of melting, especially without a flux,
had a considerable bearing upon the results obtained. The main
point was that the authors gave no evidence that if the gun-metal ha d
been overheated and contaminated with oxides and sulphur gases
(mechanically included or dissolved in the bronze) and then simply
left in the crucible without stirring or treatment with chemical de-
oxidizers imtil the temperature fell to the specified limits, the defective
metal would be thereby sufficiently improved to give sound instead
of unsound castings.
* Oomptes rendus, vol. cliii., No. 4, July 24, 1911.
Communications on Carpenter and Elam's Paper 205
The authors stated on p. 155 (par. 2) that oxide films frequently
accompanied the " eutectic " in 88 : 10 : 2 bronze, but they should
have called this constituent the " eutectoid," as suggested by Professor
Huntington.* Professor Carpenter there referred to this " eutectoid "
as a " peritectic," but there was no uniformity in naming this delta
constituent, which was sometimes called a " complex " and even
referred to as " bronzite " in America.
On p. 156 (par. 3) the correctness of the writer's determination of a
low casting temperature of gim-metal, as recorded in his paper to the
Institute in 1910,t was questioned. The temperature of 950° C.
was assumed to be a misprint, since the accepted melting point (so-
called) was 995° C. The latter figure was only the upper Umit of the
solidus range at which the alloy became completely liquid on heating,
but conversely, the gun-metal only started to solidify at about this
temperature. Instead of having a definite freezing point, gun-metal
had an extended range of selective freezing, and only became completely
sohd at 790° C. At this temperature Professor Carpenter J stated •
that : " There is a mixture of alpha which reacts with the liquid to
form beta." Dr. Longmmr had poured gun-metal at 965° C., and
this statement had wrongly been attributed by a practical man to
an error in pyrometer adjustment. The microstructure of the alloy
cast at this low temperature and the physical tests given by the writer
and by Longmuir showed that the metal was defective, especially
in ductility, as it had evidently been partially solid when poured, so
that it would completely soUdify in the mould very suddenly. At
950° C. the metal was in a sufficiently fluid condition to be poured,
although with difficulty.
On p. 157 (par. 7) the addition of zinc before the tin in preparing new
gun-metal from its ingredients was described, but in many foundries
it was customary to add the zinc last on account of the loss it sustained
by volatihzation if added before the tin. Whilst it was common
practice for bronze moulders to cool the metal in the crucible after it
left the furnace until the temperature was correct for the particular
size of casting they were making, the founders had to judge the right
temperature needed for the mass of metal required to fill the mould.
Thus the unsoundness due to blowholes got with excessively hot metal
was minimized, but the tendency to produce porosity was not lessened
by the cooHng of the metal having expelled the gases taken up in the
furnace, unless agitation of the molten metal was effected by poling.
The most generally accepted explanation of the soundness accompany-
ing lower temperatme pouring was that the metal ran less briskly
and with less agitation in the pouring vent, so that the sulphurous
gases in the metal were not oxidized. They therefore did not lose
solubility in the molten alloy so readily as in the case of rather hot
* Journal of the Institute of Metals, No. 1, 1913, vol. ix. p. 174.
t Ibid., vol. V. p. 251.
% Ibid., No. 1, 1914, vol. ix. p. 174,
206 Communications on Carpenter and Elam's Paper
metal, and thus the gases did not separate when the metal solidified
and so form porous places in the casting.
Mr. Wm. Ramsay (Birkenhead) wrote that he would like to express
his congratulations to the authors for their most important and inter-
esting contribution to the literature of Admiralty bronze. He felt
sure their work would be appreciated and have a far-reaching influence
on foundry practice.
It had been recognized for some considerable time — or perhaps he
should have said suspected — that the inclusion or occlusion of gases
in copper alloys had an important bearing on their mechanical qualities.
But, up to the present, the nature and composition of these gases
were more or less speculative.
From his point of view the presence of hydrocarbons came as a
surprise, also the fact that the difference between the gases of the
sound and the unsound bronze was more quaHtative than quantitative,
and that in the sound metal they were in solution and in the unsound
free. He hoped the authors would continue their research and com-
municate the results of their examination of alloys prepared in the
electric furnace.
It was obvious that the gases they had so far collected were largely
the products of interaction at high temperature, and he would like
to see an attempt to collect them at normal temperature. He would
suggest that the bronze be dissolved in vacvx) in mercury, possibly
with the aid of gentle heat to render the resulting amalgam fluid.
If this method were successful he thought one could reasonably assume
that the gases pumped out would be in the same state of combination
as they existed in the alloy, and he ventured to predict that they
would prove to be much simpler in composition and uninfluenced by
the rate of extraction.
The effect of temperature as regulating crystal growth and other
features was also known and made use of, but the authors' discovery
that the alloy could be rendered sound or unsound in a reversible
manner by temperature alone, was of the utmost value, since many
foundry men regard " gassed " metal as beyond recovery or only to
be rectified by " physic," such as phosphorus or other deoxidizer.
Personally he could speak well of deoxidizers, although others equally
quahfied to express an opinion did not consider them of value in
connection with the alloy in question.
The foundry in which he was interested was mainly devoted to
Admiralty bronze. At one time there was no scientific supervision,
and the results were very erratic. Sometimes good castings were
produced, and then, without any apparent change in the practice or
material, a bad run was experienced. Some eight or nine years ago,
when he became interested in the difficulty, he was soon forced to the
conclusion that it was purely a matter of temperature. A number
of experiments were carried out and pyrometric observations taken,
with the result that he laid down the limits of pouring temperature as
Communications on Carpenter and Elam's Paper 207
between 1100° C. and 1170° C. They had adhered to this as closely
as was practicable with most gratifying results, any failures being,
as a rule, traceable to non-metallurgical causes.
These Umits were somewhat lower and narrower than those laid
down by the authors, and he thought their success might possibly be
due to the foundryman erring on the high side, since he had a whole-
some dread of cold metal, also to the fact that their foundry pyrometer
was a somewhat rough instrument and might read low.
He might be a bit conservative, but once good practice was
established he was inclined to let well alone, and it was very gratifying
to know that their practice, even though they did not know the reason
underlying it, was confirmed by such an eminent authority as Professor
Carpenter.
A great deal. had been written about improving bronze castings by
heat treatment, annealing, &c. While admitting that it might be
possible to improve a bad casting by these means, he questioned very
much whether a good one could be bettered. He held that the correct
method was to make a sound casting in the first place, especially since
the authors had shown it to be such a simple matter.
Professor Carpenter and Miss Elam did not appear to have made
any mechanical tests in connection with their work, and he would
like to suggest that if these could be appended it would add greatly
to the value of the paper. Personally, he did not consider that mech-
anical tests represented everything, and, for reasons which he did
not need to mention, he was as much opposed to a very high tensile
result as he was to a very low one, but from the Admiralty standpoint
tensile strength and elongation were almost the only criteria, and had
to be taken into consideration. The Admiralty specification requiring
not less than 14 tons tensile strength was responsible for a curious
misunderstanding. Engineers very properly based their calculations
on this figure, but in the mind of some of them, and even some
metallurgists, this minimum had been inverted into a maximum.
Quite recently a metallurgist of some repute read a paper on the improve-
ment of bronze, from which it was quite evident that he laboured under
this delusion. As a matter of fact, it was fairly easy to reach 21 or
even 22 tons, but, as he had indicated, there were certain objections to
such high results, and he preferred an intermediate figure.
In his experience, failure of a casting under hydraulic test might
originate from at least two causes. Blowholes were sometimes
responsible, but, unless they were extensive and communicated,
they did not cause much trouble. The chief cause appeared to him to
be an excessive and badly distributed 8 constituent. Heat treatment
might entirely remove the S, but was incHned to leave an empty net-
work where it previously existed, rendering the casting more porous
than before. On water testing, the casting might appear tight, but
if a fresh cut was taken over the machined surfaces leakage would
frequently reappear in an aggravated form. From this he concluded
that the entrances to the pores were merely blocked by oxidation
208 Communicaiions on Carpenter and Elam's Paf'
products. Slight leakage due to blowholes or streaks of oxide mig;
frequently be obviated by caulking, but if the defect was due i
improper distribution of the 8 constituent the hammering genera [
shattered it completely, so that the casting might leak worse thij
before. Many of the expedients suggested for the betterment
defective bronze, while they might be perfectly satisfactory in tl
laboratory, were utterly impracticable on the commercial scale, and
was refreshing to find a method which had the merit of being at on(
scientific and easy of apphcation in the foundry. The subject was
the highest importance both from a national and a commercial aspec
and if Professor Carpenter and Miss Elam would extend their wor
he was siu-e it would prove of the greatest value to brassfounders.
Mr. R. T. RoLPE (Bedford) wrote that the authors were to b
congratulated on their valuable contribution regarding the condition
leading to the production of sound and unsoimd castings of tha
alloy, and upon the way in which they had overcome the experimenta
difficulties involved. At the same time he thought that a valuabk
supplement to the work already done would have been to determine
the tensile strength of that alloy as cast at different temperatures
chiefly because the tensile test in itself afforded a criterion in com
paring the soundness of different castings. In an unsound test-bar
the tensile strength of the material at any cross-section was reduced
proportionately to the area of the cross-sections of the cavities cut.
Again, the tensile test was the most important employed commercially,
and it was also not attended by the same experimental difi&culties
as the investigations that had been carried out.
Furthermore, the conclusions arrived at if a thorough investiga-
tion of that test, using several different brands of copper, had been
Copper.
GuD-Metal Cast from same.
Brand.
Per Cent, of
Arsenic.
Mean of
Average Ulti-
mate Stress.
traces
0-30
0-75
114 tests
172 „
10 ,,
Average Elonga-
tion per Cent,
on 2 In.
16-6
15-5
14-4
14-3
12-4
7-4
Admiralty specification
140
7-5
carried out, would certainly have modified the method of stating some
of the conclusions arrived at by the authors. He did not suggest that
any of the conclusions were incorrect, but he was afraid there was a
danger of No. 2 on p. 174 being applied to a greater extent than was
justified. For example, there appeared to be no doubt whatever
that the nature of the copper used made a great difference to the
Communications on Carpenter and Elam's Paper 209
tensile strength of that alloy. He was not referring to the results
of a few experimental test-bars, but to the results obtained in a com-
mercial foimdry from very large pump castings obtained over long
periods of time during which difierent brands of copper were in use.
The results obtained from each brand of copper were quite consistent
and were quite different from those of the others. These results
were as shown on p. 208.
The reason for the small number of castings made from No. 3
brand was the unsatisfactory tensile results, due to the large quanti-
ties of the alpha-delta eutectoid invariably foimd. A typical micro-
structure of the gun-metaLs produced from each of the brands had been
previously figured, and complete analyses of those three different
brands of copper were also given.* Brand 1 was an electrolytic copper,
and Brand 2 was Rio Tinto.
Some of the work already published on results of casting the
88 : 10 : 2 alloy at different temperatures was a little contradictory,
and some views that had been expressed appeared to be based on
insufficient experimental evidence, but the safety range of 1120° to
1270° C. of Karr and Rawdon appeared to be confirmed by the work
of the present authors.
In the foundry with which the writer was associated, the conditions
of working were such that casting was always carried out within those
temperatures, not by design, but by virtue of the experience of the
furnacemen. Melting was carried on in 200 lb. and 400 lb. coke-fired
Morgan tilting furnaces, and in the case of larger quantities of metal
in coal-fired reverberatories holding about 3 tons. In several different
series of tests carried out at long intervals over a period of five years
he had not found a temperature exceeding 1240° C. at the moment
of pouring. It must, of course, be remembered that a large ladle was
never poured as soon as the metal was tapped out of the furnace,
but some little time elapsed before it was got into position above the
mould. Again, if the molten metal were considered by the furnace-
men too hot, it was allowed to stand a short time to reach a suitable
temperature, or cooled down by stirring in pieces of scrap of the same
composition.
The following might be regarded as approximate average tempera-
tures for the two kinds of furnaces :
Coal-fired Reverbera-
tory Furnaces.
Morgan Tilting
Furnaces.
Quantity of metal melted
Temperatures of metal:
In furnace before tapping
In ladle after tapping ....
In ladle before pouring.
3 tons
1350° C.
1300° C.
1200° C.
200 and 400 lb.
1300° C.
1250° C.
1200° C.
* The v.riter in Proceedings of the British Foundrymen' s Association, 1914-1 5, pp. 88-1C8.
VOI^. XIX. p
210 Communications on Carpenter and Elam's Paper
Results of a representative series of tests, in wliich two bars were i
cast at each of the temperatures 1220°, 1160°, 1110°, 1060°, 1030°, i
and 1000° C. were plotted below (Fig. A.) : [
o
\
0
-ULTIMATE STRCS;
«
e
\
1 ^^'
--"'* *
V"""^ ' •
\_
EuONCATlON -^
"■\ \
<>
•
\ \
\ <
(
" 0 ^
«
'^yielO point
~^^
\
\
\
1
(
1220 1200
1160 1150
1060 1050
1000
CASTING TEMPERATURES— (SERIES 3)
Fig. A.
In those tests 200 lb. of the metal was melted in a Morgan tilting
furnace, and the cylindrical bars, 1 in. in diameter by 7 in. long, were
rast in green sand. The temperatujes recorded were those of the
metal in the shank ladle before poiiring into the mould, and were
doternuned by means of a Foster pyrometer (nickel-chromium and
nickel), reading a little above 1.350° C. The accuracy of that instru-
ment was checked against both a Ferv radiation pyrometer and a
Communications on Carpenter and Elam's Paper 211
platinum, platinum-iridium pyrometer made by Paul, the maximum
variation between the three at any of the temperatures in question
being S° C.
In practice, pouring would never be carried out at so low a tempera-
ture as 1000° C, when the metal was in a very pasty condition and on
the point of solidifying.
With regard to the large pump castings (32-36 in., 26-32 in., 23-27
in., &c.) already referred to, it might be said that their soundness was
judged commercially by subjecting them to a specified hydraulic test of
25 lb. per sq. in., and unsoundness was quite unknown.
The sizes mentioned were all cast in halves, which varied in weight
between 10 and 30 cwt., and the maximum thickness of metal in the
walls of those castings was -/^ in. Out of several hundred of those
castings over a period of about sixteen years only three wasters could
be recalled, one due to the top half of the mould floatingf and two
due to cores shifting. There was no question as to soundness in those
castings.
It was a little to be regretted that when such an investigation
as the present one was made, that commercial methods of testing
castings were not invariably appUed at the same time as the other
more scientific methods. When they were not, the value of the con-
clusions, especially when they did not march with usiial (and often
well-grounded) practice, was to some extent vitiated in the opinion
of the " practical man," as he was often termed.
Again, conclusion 4 on p. 174, although quite correct in one sense,
made no allowance for blowholes caused by the liberation of steam
from the walls of a mould by contact with the molten metal. Those
had been shown by H. S. Primrose * to differ from gas-holes caused
by the disengagement of gas from the molten metal, in the following
way:
" The steam-holes were found in the metal near the surface, and
were accompanied by a structure in the alloy similar to that got in
casting in a chill mould instead of sand. The gas-holes were generally
deep-seated, and the structure of the metal was quite normal, but of
course seriously weakened by the presence of the cavities left by the
gas." He had noticed this difference at times himself.
The references given below,f as to the efEects of casting at different
temperatures and the production of sound or unsoimd castings of
that alloy, were additional to those he had already mentioned Tor
those given by the authors of the paper. Their work certainly afforded
much further valuable information of the properties of the
material.
* Proceedings of the British Foundrymeii's Association, 1912-13, p. 388.
t Longmuir, Journal of the Iron and J^teellnstitiite, 190G, extracted by W. H. Hatfield in
" Cast Iron in the Light of Recent Rescnirl;," 1912 ed., p. 106. H. S. Primio=e on " Practical
Heat Treatment of Admiralty Gun-Metal," Journal of the Institute of Meial-, No. 1, 1013,
vol. ix. p. 158. Ibid, on "Admiralty Gijn-M:-tal," Metal Industry, Nc<;. 9, 10, 1915, vol. vii.
p. 295 ; also Feb. 2, 1917, vol. x., 5, p. 105.
212 Communications on Carpenter and Elam's Paper
JMr. H. J. Young (Wallsend-on-Tyne) wrote that the paper was
as refresliing as many were the reverse. Apart altogether from the
correctness of the authors' conclusions, the paper possessed the unusual
and welcome feature of dealing with a practical matter in a practical
manner. It was of extreme interest to brassfoimders, who would
appreciate the authors' simple wording and nomenclature. Their
results were plain and their conclusions bold, and though many f oimdry-
men would disagree with them they would gather knowledge]|^by so
doing.
By this class of reader the paper would be held to embody three
statements — firstly, that the alloy might be safely overheated to any
extent and any number of times, provided that it were poured at the
correct temperature ; secondly, that " cold " pouring was not so
dangerous as " hot " ; and, lastly, that the nature of the copper and
its various impurities mattered but little. It was unlikely that these
statements would be palatable to most foundry men.
The writer thought that the paper contained a good case for quick-
melting furnaces and " tilters," also for pyrometers, but considered
that it was a pity the authors did not use a pyrometer of the type
they appeared to recommend for the work. The 88 : 10 : 2 allo}^
gave other troubles than those dealt with in the paper.
It was an alloy usually specified for certain castings of peculiar
pattern and with test-bars attached, such castings suffered most
grievously from porosity in certain places known to those whose business
it was to make many of these castings.
The writer's experience was that if a fpundryman took any inferior
brand of copper and grossly overheated his alloy and cast it at the
correct temperature, he would be hkely to get either a bad casting or
a low test. Supposing, on the other hand, that he chose the best copper
and did not overheat and did cast at the right temperature, it was
still likely that he would meet trouble, unless he had knowledge and
experience of several precautions not mentioned in the paper.
It might be that the authors did not intend any such sweeping
conclusions to be drawn, nevertheless they made several remarks
which led in that direction.
The writer's experience was that control of pouring temperature
was a sine qua non, and one of many, in successful casting.
Professor Carpenter and IVIiss Elam, in further reply to the
discussion, and in reply to the written communications, wrote that it
was clear from these that certain misunderstandings existed with regard
both to the object of the paper and some of the deductions contained in
it. Accordingly they would deal with these in the first instance, and
also with points which had been raised by more than one contributor
to the discussion.
1 Their object in undertaking the research had been, as stated
on p. 156, to obtain fuller information than existed as to the exact cause
Aiithors' Reply to Communications
213
or causes of iinsouiidness in castings of Admiralty bronze, and if pos-
sible to devise a remedy. This was the problem as put before them
by Mr. Dewrance. Many contributors to the discussion considered
that mechanical tests should have been carried out on the alloys cast
at various temperatures. This aspect of the matter, while no doubt
subsidiary, had not been lost sight of, and in all cases test-pieces were
cast from the same melt as the main casting. Since the publication
of the research there had been so many requests for data as to the
mechanical properties of the alloys cast at different temperatures
that these had been machined and mechanical tests carried out, and
the results were given below. Moreover, in one series of casts test-
pieces were machined from the main castings and tested, and these
results were also included. ,
A. Teds on Bans Cant nearly to Size and then Machined.
Casting Temperature.
Ultimate Stress.
Tons per Sq. In.
1
Percentage Elongation
on 2 In.
°C.
/1445
Scries I. - 1225
(1137
fl396
Series II. . 1235
ill35
9-64
12-56
15-92
10-36
16-48
16-72
50
8-5
150
7-5
160
14-0
It would be seen that in the first series both the ultimate stress
and the percentage elongation improved, as the casting temperature
was lowered, and that in the second the results obtained at the two
lower temperatuxes were good and almost identical. In both cases
the ultimate stress of the alloy cast at the highest temperature was
much below that required by the Admiralty specification.
B, Tests on Bars Machined from the Main Castimjs.
* Broke outside gauge marks.
f Broke at gauge mark.
Casting Temperature.
Ultimate Stress.
Tons per Sq. In.
Percentage Elongation 1
on 2 In. 1
°C.
,1395
1395
<, . TT 1235
Scries II.. ^235
1135
1135
9-32
8-32
12-44
13-48
15-52
12-80
9-0*
— t
18-0
22-0
28-0
17-0
^14 Authors^ Reply to Communications
As was to be expected, tliesc castings gave a lower ultimate stress
tliau the bars cast nearly to size, and in only one out of the six cases
did the figure exceed the minimum prescribed in the Admiralty specifica-
tion. But the alloys cast at 1235° and 1135° C. had an unusually
high elongation figure. Here also pieces machined from the alloys
cast at 1395° C. had very inferior mechanical properties.
An analysis of the alloys mentioned in Series I. and II. gave the
following results :
Scrips I. Scries TI.
Per C'cnt. Por Cent.
Copper 88-06 88-08
Till 10-38 10-2il
Zinc 1-52 l-.W
99-96 99-95
The lowness of the zinc was due to the excessive overheating of the
alloy adopted for the experiments in question.
2. Their statement on p. 172 that the problem of obtaining sound
castings was " essentially one of temperature control and nothing
else " had been widely misunderstood. In making it what they had
in mind was the following case.
A foundry is making a particular type of casting. For a time all
goes well. Then suddenly, with no apparent change of procedure,
the castings obtained are unsound. What is the cause ? Is it a change
in the materials used or in the temperature, these being the factors
most hkely to vary, all other conditions being as far as is known
kept constant ? Or if not either of these, what is it ? This was the
problem presented to them by Mr. Dewrance. Their conclusion was
as had been stated above.
Many contributors to the discussion considered that in saying
this they had ignored many factors which are essential to the
production of sound castings — e.g. correct design of pattern, properly
dried mould, adequate venting, correct rate of pouring, &c. Nothing
was further from their intention, for they assumed that these conditions
were duly observed. None of them was altered in the case con-
sidered above. They were all, as far as Avas known, kept constant.
Mr. W. Ramsay (Birkenhead), however, had interpreted their con-
clusion exactly as they had intended it, and his remarks put the
case so well from the practical standpoint that they ventured to quote
the following extract from them :
"... The foundry in which he was interested was mainly devoted
to Admiralty bronze. At one time there was no scientific supervision,
and the results were very erratic. Sometimes good castings were
produced, and then without any apparent change in practice or material
a bad run was experienced. Some eight or nine years ago, when he
became interested in the difficulty, he was soon forced to the con-
clusion that it was purely a matter of temperature." This was exactly
Authors^ Reply to Commiinicaiion^ 215
the case the authors had in luiud, and jMr. Ramsay's solution was
precisely the same as theirs.
3. They were gratified to note from the discussion that the tempera-
ture control advocated by them as the most suitable practical method
of ensuring sound castings was in use in several works. The remarks
of Mr. Thornton Murray, Mr. Cleghorn, Mr. Brook, Mr. Longmuir,
Mr. Parker, Mr. Eamsaj', and ]Mr. Rolfe were very much to the point
in this connection, and should be noted. In cases where a works was
in doubt as to the most suitable pyrometer to apply in a given operation,
the wisest plan was to consult a pyrometer maker, tell him the precise
conditions under which the instrument would have to be used, and
exactly what was required. Valuable information with regard to
the protection of pyrometer tubes plunged into molten alloys would
be found in Dr. Rosenhain's remarks (p. 186).
4. Many contributors to the discussion, both verbal and written,
appeared to have failed to grasp one of the main points which the
authors considered they had established and certainly done their
best to make clear — viz. that the difference between a sound and an
unsound casting was neither in tl^ total volume of the gas it contained
nor in its composition. The experiments designed to extract the gases
showed that even in vacuo three meltings weie sometimes necessary
at 1200° C. before constancy of pressure was reached. This being
so the removal of gas at atmospheric pressure must be nmch more
difficult. There was nothing to indicate that sound castings contained
less gas than unsound castings.
Having dealt with these four points in a general way the authors
would no\\ take up such questions as were not covered by what they
had already written.
5. They were particularly indebted to Mr. Dewrance for his generous
appreciation of their work, and were glad to note that he was
in sympathy with their proposal for the more extended use of the
pyrometer. They entirely endorsed his view that once a skilled
founder had learnt the proper use of such an instrument it would
probably be sufficient in his hands if a certain number of check tests
were carried out on any given day. Practical men did not always
realize how greatly the apparent temperature of the molten bronze
could vary from day to day, or even during the day, owing to variations
in atmospheric conditions.
6. With regard to Commander Jenkins' question, they had had
an opportunity of examining the specification of the phosphor-bronze,
and also some unsound castings he had kindly supplied. From the
former it appeared that the temperature of incipient solidification
was much the same as in the case of Admiralty bronze. Probably,
therefore, the pouring temperature should be within about the same
limits as those recommended in the paper. From 1200° to 1150° C
would probably be the safest range.
7. Mr. Thornton Murray— and Mr. Rolfe also— had raised the
216 Authors* Reply to Communications
question as to the influence of a particular brand of copper on the
mechanical properties of the bronze obtained. They had not meant
to convey the impression that all brands were alike in this respect,
but only as regarded the soundness of the casting. They quite agreed
that differences in the amounts of impurities in the copper would
influence the mechanical properties of the bronze castings made from
it. Mr. Murray's suggestion that such impurities would probably
influence the solubility of the gases and the equilibrium of the gaseous
mixture was qiiite plausible. He was justified in drawing attention
to the high liydrogen figure in, column 2 of the gas analysis given on
p. 166, and in pointing out that it was more than could be derived from
a gas consisting of pure hydrogen sulphide in the corresponding place
in column 1. They had been puzzled by it and were unable to explain
it, and agreed that it was a case for further investigation.
8. They noted Professor Edwards' interesting suggestion as to
a method of keeping the temperature of the crucible constant during
its passage from the furnace to the mould, and thought that there
were cases where it might advantageously be tried. They agreed
with him that for many purposes for which it was still used Admiralty
bronze could with profit be replaced by one or more of the now numerous
non-ferrous alloys available. .
9. Dr. Hatfield's reference to practice in steel metallurgy designed
to prevent segregation of gases was useful and to the point. The
problem in that case was certainly more difficult than with Admbalty
bronze where, as j\Ir. Cleghorn pointed out in his own practice, there
was no need to go above 1180° C. The temperatures in steel making
were between 400° and 500° C. higher. A typical analysis of the
bronze for which he asked was given on p. 214.
10. Mr. Johnson asked whether the black deposit mentioned on
p. 164 might not be arsenic. The answer was " No." The volume was
much too great. The black film alluded to on p. 165 was certainly
cupric oxide, as they had been able to show by analysis. He drew
attention to the density of one of their castings (9 "00), pointed out
that it was higher than that of copper, and asked for an explanation.
A sijnple calculation based on the specific gravities of the components
of the Admiralty bronze would give him the explanation. There was
no reason for supposing that the carbon dioxide and monoxide figures
in the lower table on p. 167 had been mixed, although he was quite
correct in pointing out that in all the other analyses the carbon monoxide
was in excess of the dioxide. 'He asked whether dissociation of water
vapour in the quartz tube at 1100° G. could be regarded as a source
of the large volume of hydrogen observed when the gases were main-
tained in contact with the molten alloy. The answer to this was
" No." His final suggestion that there might be a reaction between
oxides in the alloy and soluble gases with the production of an in-
soluble gas was one that should be considered. They had, however,
no evidence bearing on this.
Authors' Reply to Communications 217
11. They were much obliged to Dr. Rosenhain for the suggestions
he had made with regard to the protection of thermocouples.
12. They were particularly interested in Mr. Cleghorn's contribu-
tion, from which it appeared that he had some time since concluded
how vital temperature control was in order to ensure satisfactory
castings. It appeared fi'om his remarks that he was using both
methods 2 and 3 suggested by them ; and they were very glad to note
that both of them were eflficacious.
13. Much as they appreciated the compliment paid them by Mr.
Greer, who asked them to give a ruling as between the opposing views
held by two clever chemists in Scotch foundries on the advisability
or otherwise of using phosphorus in castings, they must decline the
invitation.
14. Mr, Brook asked, " What was the condition of the svdphur in
the molten metal ? " No information was available on this point.
The matter was one of conjecture only. As regarded the connection
between gas evolution and the fuel employed, all they could say was
that gas evolution was observed in all cases.
15. They were much obliged to Professor Turner for his kind
remarks, and were very glad to notice that he had solved a practical
dijB&culty in the same way as that recommended by them. They
agreed with him entirely that the gases in the alloys required much
more investigation before a well-founded theory of their reactions
could be established, and had indeed emphasised this on p. 171.
! 16. They were much obliged to Mr. Haughton for drawing their,
attention to Cartland's analysis of the gas evolved on melting brass
castings. As he pointed out, Cartland's figures were very similar to
those given in the final column on p. 168. This parallelism was interest-
ing, as indicating that the dissolved gases were very similar in both
types of alloys. With reference to the blue constituents mentioned
they had no data other than those given in the paper, but in a paper
just published by Comstock,* on " Non-Metallic Inclusions in Brass
and Bronze," very similar conclusions would be found as to the
mode of existence of zinc oxide, and the photomicrographs shown were
very similar to theirs.
17. They were much interested in Mr. Johnson's hypothesis as to
the cause of the greater difficulties encountered in producing sound
copper castings as compared with those of bronze, and they hoped he
would test it.
18. Mr. Longmuir had done valuable pioneering work on the import*
ance of casting at the right temperature, and they were much obliged
to him for the data he had quoted from his papers. As regarded the
mechanical properties given in his table, the actual casting tempera-
tures were not stated. All that was said was that the metal was
poured " at two minute intervals " from the same crucible. It was
therefore not possible to compare his results with theirs, which in each
* Jounuxl of the American Institute of Metals, March 1918.
218 Authors' Reply to Communications
case Kliowed the best values at the lowest temperature. Possibly this
was higher than No. 3 in his table. They agreed with him that it was
cUfiicult to state what was the precise casting temperature which in any
given case would give the best results. As he pointed out many
factors bore on this, and only th€ practical man could decide this by
experience. For this reason they stated their recommendation in
general terms. Broadly speaking, the larger the casting (provided
it contained no very narrow sections) the lower was the peimissible
casting temperature.
19. In answer to Mr. Millington's question as to what they meant by
" unsoundness," they would refer him to photograph No. 1, Plate VI. ,
which showed this in an exaggerated degree. They were very much
interested in his view that the specification of the 88 : 10 : 2 alloy
could with advantage be improved by raising the figures demanded
l)oth for tenacity and ductility, and that this would compel foundc]>
to deal with this alloy more scientifically. It would be well to know
what other founders thought of this opinion.
20. Mr. Murray asked whether oxides could exist in the alloy in the
presence of hydrogen. The answer to this was "Certainly." They
had frequently noticed it.
21. They were very glad to notice from Mr. Parker's communication
that exchanges of " confidence and experience " were going on between
foundries as regards their difficulties. This was highly important,
particularly under war conditions. As regarded their method of making
the 88 : 10 : 2 alloy, they noted that he suggested a different procedure.
They had followed Mr. DewT.-ance's practice in the matter. They
thanked him for the support given to their recommendation for proper
pvrometric control of casting temperatures, and for the data that he
gave for alloys of various freezing temperatures. His resume of sub-
stances he had tried with a view to what might be called the " chemi-
cal " production of somid castings was of much value, and they thanked
him for contributing it. They regretted that they were unable to give
the analysis of the Rio Tinto copper for which he asked. They could
not trace the ingots. The samples for analysis were always machined
with dry tools, and every care taken to see that they were as far as
possible uncontaminated in the process. They did not follow his
reasoning with regard to the origin of the carbon monoxide and dioxide
in their ingots, but it was incorrect to suggest, as he did, that they
might have been derived from the " combustion of ordinary organic
contaminations or volatilized grease."' They had no reason to cloubt
that the gases were present in the ingots as made, and that they were
derived from the coke or gas used in melting the alloy. With regard
to his request for fuller data about the methods used in the gas analyses,
they would refer him to statements now incorporated in the paper
(pp. 162 and 165) which did not appear in the advance copy. If he
wished to ask any specific question, they suggested he should address
it to Professor Bone at the Imperial College, who had designed the
Authors* Reply to Communications 219
apparatus they had used in their experiments. They had not
overlooked the paper by Guichard to which he alluded, though it
had not been mentioned in their paper. Mr. Parker's contribu-
tion was really another paper on the same subject as their own,
and they wished to thank him specially for the trouble to which
he had put himself in writing so valuable an article.
22. With reference to Mr. Primrose's comment on their use of the
word " eutectic " in paragraph 2, this should have been placed within
inverted commas in the advance copies of the paper. The authors
were for the moment simply following the nomenclature of Karr and
Rawdon, whose paper they were summarizing. They themselves
referred to it throughout the paper as the " 8 copper-tin constituent."
23. They were much obliged to Mr. Ramsay for his suggestion as
to liberating the gases in the alloy by dissolving it in mercury in vacuo
with, if necessary, the aid of gentle heat, and they hoped to carry
out this experiment. The residts should certainly be interesting
For the time being they were both engaged on other work which pre-
cluded this. They were interested to notice that, as a result of his
pyrometric experiments, he had laid down 1170° to 1100° C. as the
pouring limits. His lower limit was wdthin 20° of that recommended
by them, whereas his upper limit was 100° lower. In making their
recommendation they had in mind perhaps a wider range of castings
than he dealt with. Those of the small, intricate type might need
a higher pouring temperature than 1170° C His statement that this
pyrometric control had been attended by most gratifying results
might be commended to founders who were hesitating as to what
particular method of scientific control to adopt.
24. Mr. Rolfe's first and second points had already been dealt with
in replies to other speakers. In view of what he said, however, with
regard to recommendation No. 2, they wished to emphasize that
they only had " soundness " in mind when they made it. They
agreed that impurities present in the copper would influence the
mechanical properties of the alloys made from it. The percentage of
arsenic in brand 3 of the copper mentioned in his first table appeared
unusually high, considering it was used for making alloys. This
would appear from the small number of tests made with it as compared
with Nos. 1 and 2. They noted that an increase in the amount of
aS eutectoid was produced by it. Such a high percentage of foreign
metal naturally affected the equilibrium of the mixture. Mr. Rolfe's
second table was of much interest, and fitted in well with the authors'
recommendations. His figure giving the results of mechanical tests
carried out on bars cast at a series of temperatures between 1220°
and 1000° C. was of great practical value. It showed that metal cast
between 1220° and 1030° C. was, so far as mechanical properties were
concerned, satisfactory. In fact, the variation of properties was
remarkably slight. His values obtained from metal cast at 1160° C.
compared closely with theirs in Series I. and II. (p. 213).
220 Authors' Reply to Communications
25. They were extremely obliged to Mr. Young for his very friendly
commendation of their paper, and were glad to note that, from a
practical standpoint, he regarded their conclusions as correct. His
words of caution as to the possibility of too sweeping conclusions
being drawn from their recommendation as to temperature control —
to the exclusion of other factors — were quite justified, and they would
refer him to their remarks in section 2 of their reply for a statement
of their position in the matter.
26. Summing up the matter, it appeared from several of the con-
tributions to the discussion and correspondence that in their main
recommendation the authors were preaching to the converted ; that
several foundries were, and had for some time been, strictly controlling
the pouring temperatures of their 88 : 10 : 2 mixtures and found it
well worth doing so, and that many difficulties — ^inexplicable before
this control was introduced — had now disappeared. The authors
were much gratified that their insistence on proper temperature control
fitted in well with practical experience, and they hoped that their
investigation would prove of service to foundries which were in doubt
as to the best practical method of scientific control to adopt.
27. By an oversight the sulphurous gases in the mixture analyzed
by them had been returned in the tables as " sulphur dioxide and
hydrogen sulphide." This should have read " sulphur dioxide or
hydrogen sulphide." The necessary corrections had been made in
the text published in the Journal.
28. The authors were now engaged on another research which
would render it impossible for them to complete the work mentioned
in the last paragraph of the paper (p. 174). They were glad to be able
to state, however, that Professor Turner was undertaking, under the
auspices of the Research Department, a similar investigation in con-
nection with the obtaining of sound brass castings, and they hoped
that he would include in it experiments designed to test chemical
methods of control.
Anderson : Note on tJie Annealing of Akimininm 221
NOTE
ON THE ANNEALING OF ALUMINIUM.*
By ROBERT J. ANDERSON, B.S., Met.E. (Cleveland, Ohio, U.S.A.).
DuBiNCr the course of some recent tests on the annealing of cold-
rolled aluminium sheet, an examination was made of certain samples
of commercial aluminium sheet (16-gauge) which were sent to the
writer's laboratory. A brief description of the work performed is
here presented, mainly for the reason that very few accounts on the
metallography of aluminium have appeared in scientific publications.
Certain samples of supposed aluminium sheet were received with a
request for complete — so far as possible — chemical and metallogi-aphic
tests. Casual examination indicated that the metal submitted was
aluminium, and the chemical analyses confirmed this. The samples
showed the percentages of elements given in Table I. :
Table I. — Chemical Analyses of Samjiles,
Aluminium by Difference.
Percentages of Elements.
Sample
Copper.
Iron.
Silicon.
Manganese.
Aluminium.
1
trace
0-69
0-25
trace
99-06
2
trace
0-90
0-06
trace
99-04
3
trace
0-87
0-22
trace
98-91
4
trace
0-85
0-23
trace
98-92
5
trace
0-74
0-65
trace
98-71
The chemical analyses are interesting because of the variance
from the usual run of American metal, on which the average chemical
analysis is ;
Per Cent.
Copper 0-11
Iron 0-32
Silicon 0-37
Manganese .......... trace
Aluminium 99-20
* Presented at Annual General Meeting, London, March 14, 1918.
222 Anderson : Note on the Annealing of Aluminium
The iron in the metal examined is rather high, while copper is present
only in traces, and the metal is evidently of an inferior grade than
best American aluminium. The hardness of the samples as received
was taken with the Shore scleroscope,with the results given in Table II. :
Table II. — Shore Scleroscope Hardness of Samples.
Sample Marked.
1
2
3
4
6
Hardness Number.
8
6
8
7
9
The Shore hardness values indicate that none of the samples was in
the annealed condition ; they had been hardened either by cold work
or strain, or else had been partially annealed with a consequent fall
in the Shore values. These hardness numbers do not indicate severely
worked aluminium ; a commercial 16-gauge sheet (with over 99 per
cent, aluminium, and impurities normal) would have a Shore value
of 13 to 15 when in the severely worked condition, and a Shore value
of 4.-5 in the annealed state.
Microscopy.
Microsections were secured, polished, and etched, and examined
under moderate powers. The results of the microscopic examination
are summarized in brief in Table III. :
Table III. — Microscopy of Samples.
Sample Marked.
Remarks.
1
2
3
4
5
Amorphous ; indicating a hard-worked sheet.
Grain boundaries visible, but greatly distorted.
Amorphous ; similar to 1.
Amorphous ; similar to 1.
Crystalline grains elongated in the direction of work.
A consideration of the chemical analyses, Shore values, and microscopy
is interesting. Sample 1 appeared to consist of amorphous material,
but the scleroscope hardness was only 8, so that this sample had
possibly been cold-rolled and then partially annealed. Aluminium may
be softened by annealing so that its Shore value is around 4-5, and
still present an amorphous appearance under the microscope. Samples
2, 3, and 4 might be judged in the same way ; the high iron would
make for greater hardness than would be otherwise expected. Sample
5 had a higher Shore value than any of the other samples, which would
appear contradictory in the face of the chemical and microscopic data.
(Rediii-cd 50% in reproduction.)
Plate IX.
I
Fig. 1. — Sample 2, as received ; etched witli
Hjdrofluoric Acid ; X 100 diameters.
Fig. 2. — Sample 3, as received ; etched \\
Hydrofluoric Acid ; X 100 diameters.
"wm
'-■*■.
■ t
Fig. 3. — Sample 5, as received ; etched with
Hydrcfluoric Acid ; x 215 diameters.
Fig. 4. — Sample 1 after annealing; etc
with Hj'drofluoric Acid ; X 50 diamet
gTain size 57 per sq. mm.
Fig. 5. — Sample 5 after annealing ; etched
with Hydrofluoric Acid ; x 100 diameters ;
erain size 150 ner sfi- mm.
Anderson : Note on the Annealing of Aluminium 223
Results of Annealing.
In order to convert the amorphous or partially amorphous metal,
in certain of the samples, into the crystalline form, a few annealings
were made. Thus Sample 1 was heated to 540° C. for fifteen minutes,
and then cooled to room temperature with the furnace — ^the cooling
taking place over night, and the annealing being performed in a small
electric furnace of the resistance type. The structure of Sample 1
prior to annealing was similar to that shown in Fig. 1 (Plate IX.), while
after annealing it was like the structure in photomicrograph Fig. 4.
In the same way, the elongated grains in Fig. 3, which is a photo-
micrograph of Sample 5, were equiaxed by a similar annealing ; the
structure of Sample 5 after annealing is shown in Fig. 5. This behaviour
is, of course, typical of metals in general, and the laws for annealing
aluminium are, in their general aspects, the same as for other metals.
Aluminium, however, exhibits a certain sluggishness toward rC'
crystallization — -as has been previously observed in the literature
of the subject — and it requires relatively higher temperatures, or
longer times, or both, depending upon the amount of amorphous
material present or the amount of deformation to bring about recrystal-
lization, than would be expected.
The effect of deformation on the recrystallization of aluminium
is instanced by a consideration of the grain size of Samples 1 and 5
after annealing (see Figs. 4 and 5). The grain size of Sample 1 is 57
grains per sq. mm., while that of Sample 5 is 150 per sq. mm. The
structure of Sample 1 prior to annealing was like that in Fig. I,
obviously more deformed than Fig. 3, which was the structure
of Sample 5 prior to annealing. Both annealing treatments were
identical, but the grain size of Sample 1 is considerably larger than
that of Sample 5.
ii24 Discussion on Anderson's Note
DISCUSSION.
Mr. D. Hanson, M.Sc. (Teddington), said that the author drew
attention to the very unusual analyses (p. 221), especially the silicon
contents of the different sheets, and in particular to No. 2, in which
the content was as low as 0*06 per cent. Turning from that to the
hardness of the samples on the next page, it would be noted that the
hardness varied with the silicon content — that the hardness increased
with increasing silicon content. Now it had been recently shown that
silicon was soluble in aluminium to the extent of about 1| per cent.
That was the full extent of the solubility of silicon. Under normal
casting conditions, of course, as much as that would not dissolve,
but during the annealing necessary for the rolUng an appreciable
amount would dissolve. Although the author stated that a certain
amount of annealing had been probably given to the sheets, it was
quite possible, and in fact probable, that the silicon contents were a
contributory cause to the variations in hardness. The author further
referred to the variations in grain size in the two samples 1 and 5. He
noted that with similar treatment the sample which was most deformed
gave the larger grain size. That was not a general conclusion which
applied to the annealing of all metals. As a rule, on annealing imder
the same conditions, if the annealing were carried far enough, that
metal which had been least deformed would possess the largest grain
size on further annealing.
Dr. A. G. C. GwYER (Warrington) said that the point that Mr.
Hanson mentioned, 0*06 of silicon, was a cmiosity ; he could not but
think that there must have been some mjstake. He had never heard
of such a thing at all. With regard to the scleroscope hardness numbers,
8, 6, 8, 7, 9, and so on, the author said : " The Shore hardness values
indicate that none of the samples was in the annealed condition."
That was rather contrary to the experience which he had had. He
had had a sample of very low grade metal fairly recently, and after
it had been annealed for three hours at 500°, and then for a further
period of three hours at 500°, it was still 8| on the scleroscope. So he
did not think it was quite safe to say that the hardness values showed
that none of the samples was in the annealed condition, especially
in view of the fact that the metal was all of low purity or comparatively
low, especially No. 3, and he was very suspicious of No. 2, because
with 0-90 of iron the silicon would very Hkely be nearer 0*6 than 0*06.
He confirmed Mr. Hanson's remark with regard to the effect of work
on grain size.
Author's Reply to Discussion 224a
COMMUNICATION.
Mr. Anderson wrote, regarding Mr. Hanson's remarks, that it
was not his (Mr. Anderson's) intention to imply that the hardness
of the samples increased with increasing silicon content, nor did it
seem apparent to him how, in view of the uncertain condition of the
samples, this should have been deduced. It was probable that the
silicon contents were contributory to the variations in hardness.
Kegarding Dr. Gwyer's remarks as to the silicon content of Sample 2,
the writer had no reason to suspect that there was any mistake. He
had at hand a number of analyses of American aluminium which
showed low silicon — from 0'15 to 0*20 %. Certain aluminium used for
melting-point determinations at the Bureau of Standards contained
0-02 % copper, 0-12 % siHcon, and 0-15 % iron.
Dr. Gwyer'e experience with anneahng low-grade aluminium was
interesting ; he (Mr. Anderson) had never found anything Hke that.
With reference to the scleroscopic hardness of so-called annealed
aluminium sheet, he had arbitrarily, in order to have had some more
or less rational basis to start from, chosen Shore hardness number
4-5 (regular hammer) as the degree of hardness possessed by " annealed "
aluminium sheet, and that hardness was used in commercial practice
in America. Aluminium of that hardness was practically as soft as it
ever could be, although instances had been observed where the Shore
hardness number was as low as 3-5. On that basis, then, sheet with
a hardness of 6 to 9 would not have been considered as annealed.
With reference to the statement by Mr. Hanson as to grain size,
and confirmed by Dr. Gwyer, the facts in the case were that the
compHcations leading to grain growth on heating metal which had
had prior plastic deformation were not such as could have been
explained by either Mr. Hanson's or his (Mr. Anderson's) remarks.
Roughly considered, it was true that metal which had received a
relatively hght reduction by rolUng was in the aggregate coarser grained
after anneahng than similar metal which had received a heavier
reduction. Grain growth he took to have been influenced among
other things by the original grain size, by the grain-size contrast,
and by the amount of prior plastic deformation. It had been recently
shown that for every different amount of deformation there was a
definite rapid grain growth temperature, and this temperature was
lower with increased deformation. It was entirely within reason to
hold that Sample 1, which had the greater deformation, was more
" critically " deformed for the temperature employed than was Sample
5, which had the lesser deformation, as evidenced by the photomi-
crographs. In other words, the temperature used, more nearly
approached the germinative temperature for that deformation of
Sample 1 than for the deformation of Sample 5. It was also possible
to conceive of occluded alumina (AI2O3) in aluminium acting hke a
"sonim" in steel or hke thorium oxide in tungsten, which opposed
grain growth and accordingly raised the germinative temperatiure.
VOL. XIX. Q
825 Birmingham Local Section Annual Report
BIRMINGHAIVI LOCAL SECTION.
Annual Kbport, Presented April 30, 1918.
Session 1917-1918.
Thi Eighth Session of the Section may be considered a very
satisfactory one. The membership is as follows :
Members ...... 138
Associatee ..... 48
Total . . . .186
At the end of last session the total membership was 82.
The following meetings were held during the past session :
1917.
Tuesday, Oct. 16. Lecture on the " Scientific Spirit in the Metal Trades," by
ProfeBsor T. Turner, M.Sc.
,, Nov. 20. Chairman's address. Subject, " Co-operative Labora-
tories," by Stakxky Eveeed.
„ Dec. 18. Paper on " Copper Alloys, Brass and Bronzes," by H. L.
Reason.
1918.
„ Jan. 22. Paper on the " Relation between the Laboratory and the
Workshop," by W. R. Babclay.
,, Feb. 19. Paper on " The Scope of the Works' Laboratory," by
F. C. A. H. Lantsbeeey, M.Sc.
„ March 6. Paper on " Pyrometry and its Application in the Metal
Trades," by C. M. Walter, B.Sc.
The average attendance at these meetings was :
Members and Associates . . .38
Visitors 33
Total .... 71
This is a marked improvement on last session, when the
attendance averaged 29.
Birmingham Local Section Annual Report 226
The following officers for session 1918-19 have been duly
elected :
Chairman.
F. C. A. H. Lantsberry, M.Sc.
Past Chairmen.
G. A. BOEDDICKER.
Professor T. Turner, M.Sc, A.E.S.M.
C. H. Barwell.
S. Evered.
Honorary Secretary.
W. H. Henman.
Honorary Treasurer.
S. M. Hopkins.
Committee.
G. BiLL-GozzARD. L. J. Meyrick.
Dr. H. W. Brownsdon, M.Sc. H. L. Reason
H. W. Clarke. A. Spittle.
F. Johnson, M.Sc.
Associate Member.
R. H. Davies.
227 Notes for Authors on the Preparation of Papers
NOTES FOR AUTHORS ON THE PREPARA-
TION OF PAPERS FOR "THE JOURNAL
OF THE INSTITUTE OF METALS."
The following notes, which have been drawn up by the Pub-
lication Committee, are intended for the guidance of prospective
authors who may prepare papers for presentation before the
Institute of Metals. The notes replace those previously published
in Vol. XVI.
(A) Form of Papeb. — (1) The MS. should he so prepared by careful
revision that few alterations should be found necessary on revising
the proof.
(2) Papers should, whenever possible, be typed with double-line
spacing.
(3) In the case of lengthy Papers a Summary should form part of
the Paper.
(4) A separate Abstract, not exceeding 200 words, and suitable for
pubhcation in the general press, should also be provided.
The Publication Committee are of the opinion that in many cases
the value of Papers would be increased by Authors giving more details
than are often included of the experimental methods adopted in
obtaining the conclusions arrived at or the results described. But,
in order to avoid obscuring main issues with a large amount of detail
of this character, it is suggested that such matter be given as an
Appendix.
(B) Nomenclature of Alloys. — Authors are invited to adopt
the Alloy Nomenclature, as recommended in the " First Report of the
Committee on the Nomenclature of Alloys " {Journal of the Institute
of Metals, No. 1, 1914, vol. xi.). The Recommendations are as
follows :
(1) Brass. — The term " brass " is to be used as an abbreviation
of the words " zinc-copper " as employed in the systematic nomen-
clature. Thus when the word " brass " alone is employed it shall
denote an alloy of zinc and copper only, containing more copper than
zinc, i.e. containing over 50 per cent, of copper. When an alloy in-
tentionally containing a third metal, such, for example, as tin, is to
be denoted, the name of the additional element shall be used as a
prefix, precisely as in the systematic nomenclature. Thus an alloy
containing tin 1 per cent., zinc 29 per cent., and copper 70 per cent,
would be called " tin-brass." If additional metals are present their
Notes* for Authors on the Preparation of Papers 228
names may also be prefixed, or the general prefix " comp." or " com-
plex " may be used if it is not essential to mention the other elements
specifically.
(2) Bronze. — The term " bronze " is to be used as an abbreviation
of the words " tin-copper " as employed in the systematic nomen-
clature. Thus when the word " bronze " alone is employed it shall
denote an alloy of tin and copper only, containing more copper than
tin, i.e. containing more than 50 per cent, of copper. The presence
of one or more intentionally added metals shall be denoted in the
same manner as has been indicated above in the case of brass.
(C) Abbreviations. — Commonly accepted abbreviations should
be used, as, for example, c.c, mm., lb., ° C. With regard to the latter,
temperatures should invaribly be given in Centigrade, though Fahren-
heit may be added if thought desirable.
(D) Illustrations and Tables. — Authors should indicate in
the text where, as far as may be practicable. Illustrations and Tables
should appear. If Authors do not indicate this the Editor will
use his discretion in the matter. It is desirable to avoid any
rearrangement after tabular matter has been put into page form.
(E) Plates. — As the Institute desires to reproduce photomicro-
graphs in a satisfactory manner by printing this class of illustrations
as Plates, Authors are requested to restrict the number of photo-
micrographs as much as possible on account of the considerable expense
involved. In order to avoid the multiplicity of magnifications which
results from reducing photomicrographs in reproduction, Authors
should send photomicrographs trimmed to one of the sizes stated
below :
4" X 3" (representing 2 photomicrographs to a plate) i
n" X 3" „ 4
H' X 2" „ 6
Or a circle having a diameter the same as that of the lesser dimension
of any of the above three sizes may be adopted. Photomicrographs
submitted in accordance with the above sizes will be reproduced full
size. Authors should in every case adopt the smallest size cansistent
with adequate representation of their subject. In taking photomicro-
graphs for reproduction Authors are requested to adhere to magnifica-
tion expressible in multiples of 10 diameters. Although rigid uniformity
cannot invariably be adhered to, the following magnifications are
suggested for general use :
10, 50, 100, 150, 300, 600, and 1000.
Photomicrographs should invariably be printed on glossy paper, and
should not be mounted.
Each photomicrograph should have a title indicating the principal
features represented, but this title should not be written on the photo.
In fact, no writing should be put on the photos or illustrations of any
2-29 Notes for Atithors on the Preparation oj Papers
kind, but should be given by tlie Author on a separate sheet, so that
the printer might deal with it as might be found necessary.
The particulars given in the case of each photomicrograph (or
in the case of the Plate if these are all similarly treated) should include
the magnification (and N,A. of objective in the case of high magnifica-
tion), also the method of developing the structure (etching, &c.),
mechanical and/or heat treatment, and illumination (if the latter is
in any respect exceptional).
(F) Diagrams. — Diagrams should be made on smooth paper, or
Bristol board. Papers with rough surfaces should he avoided.
Where there is much detail in the diagrams large scale drawings are
best.
Diagrams in which there is little or no detail should be drawn the
size that they are desired to occupy within the typed area of the page
(4 in. X 6| in.). Reproductions can then be made the same size as
the drawings.
r \{G) Lettering of Diagrams. — The descriptive lettering on the
diagrams should be in pencil, to allow of the lettering being re-drawn
in a suitable size and manner for reproduction and to bring about
desirable uniformity.
A brief description should be given underneath each separate
illustration.
'■"^ Authoi-s whose Papers are accepted for publication receive 50
reprints of their Paper either with, or without, the Discussion and/or
Communications, according to their preference.
SECTION 11.
ABSTRACTS OF PAPERS
RELATING TO THE NON-FERROUS METALS AND
THE INDUSTRIES CONNECTED THEREWITH,
CONTENTS.
PAoa
Peofbbties of Metals and Allots 232
Mbthods of Analysis; Physical and Mechanical Testing; and
Pyeometey 267
fubnaoes; foxjndby methods and apflianoxs .... 281
Eleotbo-Chemisxby ; Metalloobafhy 288
BiBLIOOBAFHY 292
In the preparation of the following abstracts the Editor has had
the assistance of a staff of abstractors, including Mr. S. L. Archbutt,
Dr. C. H. Desch, Mr. D. Hanson, M.Sc, Mr. F. Johnson, M.Sc, and
Professor A. Mazzucchelli.
( 232 )
PROPERTIES OF METALS AND ALLOYS.
CONTENTS.
PAGB
I. Properties of Metals 232
II. Properties of Alloys .. e ..... . 250
lU. Industrial Applications . . 256
IV. Corrosion 264
1.—PE0PEBTIE8 OF METALS,
Acetylene^ Action on Metals. — Some experiments have been made
by W. R. Hodgkinson * to determine the action of acetylene on various
metals at a high temperature. Aluminium, cadmium, copper, lead,
tin, and zinc are unafiected by acetylene up to their melting points,
[ron, nickel, cobalt, manganese, tungsten, platinum, and palladium
are carburized, approximately in the above order, iron being the most
eactive. Nickel and cobalt are very brittle at temperatures above
200° C. Some of the metal passes into the acetylene soot which is
formed, and a nickel ware may be completely dispersed in this way,
the soot sometimes containing as much as 15 per cent, of nickel. A
mixture of acetylene and ammonia carburizes more rapidly than
acetylene alone, and less soot is formed. Iron nitride is converted
into carbide by heating in acetylene. — C. H. D.
Alumininm. — ^The past, present, and future of aluminium are
briefly dealt with by J. W. Richards. f The industry began about
the time of the invention of the Bessemer process in the middle of
last century. The great hopes of Deville were never reahzed, the
infant industry in France remaining an infant for twenty-five years.
Promising growth began in 1890 with the rise of the Hall process, and
the industry reached mature strength and development only in the
beginning of this century. The centre of the industry has moved
from France to North America, and of the approximately 100,000
tons produced annually the United States provides about two-
thirds.
♦ Journal of the Society of Chemical Industry, 1918, vol. xxxvii. p. 86.
t Metallurgical and Chemical Engineering, Sept. 1917, vol. xvii. (No. 6), p. 289.
Properties of Metals and Alloys ^33
The sources of raw material, bauxite, have not changed much in
many years. France has the largest deposits. Purification of the raw
material has developed largely in the United States, Great Britain,
France, Belgium, and Germany. The electrolytic reduction of purified
alumina requires large amounts of cheap power, in which respect
countries like Canada, Norway, and the Alps possess great advantages.
Norway in Europe and Canada in America loom up as the future
centres of production.
As a war material aluminium has found many uses. Aluminium
alloy time fuses for shrapnel have been largely used in place of brass.
The modern long-tapered rifle bullet has a tip of aluminium lying just
inside the cupro-nickel sheath ; this gives a flatter trajectory and an
increased accuracy of fire. Aluminium alloy radiators are used on
machine-guns of the air-cooled type. The explosive " ammonal,"
consisting of powdered aluminium and ammonium nitrate, is being
used in large quantities by all combatants in the present war.
Aircraft construction has absorbed large quantities of aluminium.
A large ZeppeUn contains about 9 tons of aluminium alloy frame-
work.
There is no longer any question of the status of aluminium as an
" eveiyday " metal. One of its largest fields of utihty is for cooking
utensils. In automobiles it is a necessity, and almost one-third of
all that is made is thus consumed.
With regard to its future, the author states that its use and useful-
ness will continue their rapid rate of increase ; it will become cheaper
after the war, and will rank with the half-dozen metals most useful to
mankind. The present output of 100,000 tons yearly will increase
to 1,000,000 before the middle of the century, and in net usefidness it
will stand beside copper and be surpassed only by iron and steel. —
S. L. A.
Annealing of Metals. — The general features of the working and
annealing of metals are discussed, and a review of results of Continental
workers given by C. A. Thompson.*
The influence of such operations as cold roUing, wire drawing,
in increasing the hardness of a metal is well known. The plastic
deformation which occurs during such treatment has been shown
by Ewing and Eosenhain to take place by internal shearing of the
crystals along planes of easy sHp or " gliding planes." Beilby has
proposed the theory that this slipping causes breakdown of the
crystalline structure in the neighbourhood of the gliding planes
with formation of amorphous material, to the presence of which
the altered physical properties of the metal are due. This theory
explains the fact that the crystalHne elements, persisting even after
severe cold work, are no harder than the crystals were before. The
• Faraday Society TranaacUotu, June 1917, vol. xii. pp. 30-37.
234
Abstracts of Papers
following sclerometric results by Faust and Tammann illustrate this
point :
Metal.
Condition.
Breadth of Scratch in Mm.
Load, 10 Gms.
Load, 17 Gms.
Copper .
Zinc
Cadmium
(Soft
iHard
fSoft
1 Hard , ■
(Soft ^,
iHard
0014-0-016
0016
0016-0-019
0014-0019
0022-0-027
0-022-0-027
0022-0-027
0022-0-027
0-017-0026
0019-0024
0-030-0-043
0038
The capabihty of a metal to flow, for instance in the rolls, is in-
fluenced by the development of gUding planes within the crystals.
The remarkable power of flow possessed by a metal at the moment
when, under stress, slip is occurring along the ghding planes has been
shown by Beilby, and may be attributed to the amorphous material
formed which wiU act as a lubricant between adjacent crystalline
masses.
During rolling a metal is alternately subjected to tension and
compression, which causes a progressive lowering of the elastic Umit.
Muir has proved that the true elastic Umit of a material immediately
after the appUcation of a stress and its removal is almost non-existent,
any stress, however small, producing further flow. The higher the
elastic limit, the greater the amount of energy wasted in working
a metal. fe^
In annealing preparatory to further working, therefore, it is necessary
not merely to heat the metal to the temperature required to produce
complete recrystallization of deformed material, but to soak at a
temperature sufficiently high to promote crystal growth, thereby
producing a further lowering of the elastic limit and a maximum
softening. The following results are given to illustrate the above
point :
Nickel-silver (nickel, 9 per cent.). Brinell hardness. Tests on
strip ^th in. thick, f th in. wide, annealed 30 minutes in gas-muffle.
Load, 500 kg. ; diameter of ball, 10 mm.
Brinell Hardness.
As Rolled.
Annealed at ("• C.)—
300°.
370°.
440°.
510°.
580°.
720°.
786°.
930°.
130
143
124
1
119 1 86
80
66
62
50
Properties of Metals and Alloys
235
Softening has commenced at 370° C. and proceeds at first rapidly,
then more slowly, but full softening is not obtained until a temperature
of 800° C. is reached :
Brass, 70 : 30 (Charpy).
Tensile Strength. (Kg. per sq. mm.)
Ab Boiled.
Annealed at (° C.)—
200°.
280°.
1 420°.
1
560°.
600°.
850°. ;
49-5
51-2
46-5
1
34
30
27-5
27-5
The annealing temperature for an alloy is always much higher
than for a pure metal, and the range over which most of the softening
occurs is more extended. Charpy's tests on copper illustrate this :
Copper (Charpy).
Tensile Strength. (Kg. per sq. mm.)
As Rolled.
200°.
Annealed at (° C.) —
280°.
420°.
600°.
730°.
850°.
30
30-8
30-5
221
22-2
22-2
22-0
The slight increase in hardness just before commencement of
softening in all three series of tests given above has been found to hold
very generally.
Charpy's results on anneahng of cold-worked brasses are collected
and shown diagrammatically. The temperature at which softening
starts is practically constant at 280° C. throughout the series. That
of complete recrystallization, however, rises from about 300° C for
copper to about 600° C. for the 70 : 30 brass, and then drops somewhat.
The initial temperatm-e of "burning" falls steadily from 1000° C.
for copper to about 750° C. for 60 : 40 brass. In connection with
burning of brass, Hudson has shown that the mechanically weak,
coarse structure produced by soaking at a high temperature has
perfectly satisfactory rolhng properties. Beyond a certain tempera-
ture, however, volatilization or fusion of volatile or easily melting
constituents probably occm's, which results in simultaneous loss
of strength and ductihty.
Charpy has shown the marked influence of impurities in promoting
burning. Thus a cartridge brass with lead 0 2, tin 015, began to burn
236
Abstracts of Papers
at about 800° C. The corresponding pure brass showed no deteriora-
tion at 900° C. The following tensile test results on the impure brass
are given in illustration :
As Boiled.
Annealed at (° C.).—
540°.
620°.
30
61
700°. 860°.
930°-
Maximum stress (kgms. per
sq. mm.)
Elongation per cent. .
62
3-8
32
55
29-3
65
27-6
67
26-5
56-5
*" The annealing of nickel-zinc-copper alloys (nickel-silvers) is illus-
trated by curves of torsion tests on alloys containing copper 60 per
cent, with nickel 7, 20, and 28 per cent, respectively. With 7 per
cent, nickel the available annealing range is from 650° C. to over
800° C, but with 28 per cent, a temperature of 700° C. is required to
yield the most ductile product, and at 800° C. the alloy is distinctly
" burnt." High nickel alloys of this type are amongst the most
delicate of non-ferrous alloys to obtain with maximum strength and
ductility.
With regard to the time factor in annealing the work of Le Chatelier,
Charpy, and others points strongly to the conclusion that, provided
the requisite temperature is reached time is almost without effect,
the extent of annealing being determined almost entirely by the
maximimi temperature attained. At lower temperatures, however,
time is important. Tensile strength curves obtained by Le Chatelier
for annealed hard rolled copper are shown. At 200° C. almost an
hour's soaking is required to produce the total annealing obtainable
at that temperature, but at and above 350° C. the softening is completed
in a minute or two.
Measurements of electrical resistance (Cohn) yield exactly similar
results. In this connection the nickel-silver alloy previously referred
to containing nickel 28 per cent, is remarkable in that anneahng
produces no loss of resistance. The curve for the 7 per cent, nickel
alloy shows a minimum at 400° C. Similar minima have been found
by Credner for many metals, e.g. gold, silver, copper, nickel, and iron.
A bibhography is appended. — S. L. A.
Bismuth, Allotropy of. — The specific gravity of massive bismuth
is found by J. Wiirschmidt* to be 9 80, and that of the same metal
in powder 9-70. On these grounds, the powder is assumed to contain
a larger proportion of the lighter modification, already recognized
by Cohen. This has also been considered by the author to be present
* Jdhrhuch fur Jlineralogxe, 1917, vol. i. Ref., p. 2.
Properties of Metals and Alloys 237
in bismuth amalgam. (On the hypothesis generally adopted in this
country, the powdered metal, having been subjected to mechanical
work, must contain a larger proportion of the amorphous modification,
which is specifically Hghter, so that there is no need to assume a special
allotropy).— C. H. D,
Calcium, Electrical Properties of. — Electrical measurements have
been made by C. L. Swisher,* using Kahlbaum's metallic calcium.
Wires are made by cutting the metal into pencils and draw'ing under
oil. Paraffin has an appreciable action on the metal, and the best
liquid is found to be benzene which has been kept over calcium carbide.
The specific resistance, determined in a good vacuum, is 4'6 X 10"^ ohms
per c.c. at 20° C. It increases with the temperature in a strictly linear
manner, reaching the value 13*6 X 10'^ at 600° C. The mean coefficient
is therefore about 0 00364.
The thermo-electric power of calcium is positive to lead within
the range examined, and varies from 8 "9 microvolts per degree C.
at 50° to 14-0 microvolts per degree at 400°. The Thomson coefficient
is positive. — C. H. D.^
Copper, Hardness o£ Hard-Drawn. — The relative hardness of the
outer surface and the interior of hard-drawn copper has been investi-
gated by E. H. Pierce,f with the object of ascertaining whether there
exists on the outside a hard '* skin." A number of samples of hard-
drawn copper have been submitted to Brinell hardness and tensile
strength tests, both on the surface and at varying points in the cross-
section. For the purpose of the hardness tests, drawn rods of square
section were used, and the tests were made with a ball of 0'1875 in.,
the depth of the impression corresponding to a harcbiess of 100 being
only 0 0016 in. Tensile tests were also made on samples from which
the original surface had been removed by (1) turning in a lathe, and
(2) dissolving in nitric acid. The author also enters into a theoretical
discussion of the nature of the drawing operation, which leads to the
conclusion that the wire is equally affected throughout its whole cross-
section. The experimental results completely confirm this conclusion.
In the discussion, L. Addicks states that the behaviour of hard-
drawn copper wire under torsion demonstrates the existence of a hard
skin of appreciable thickness, but that the removal of the outer surface,
either before testing the drawn wire or before the wire is drawn,
removes this skin effect. He suggests that it is due to oxide scale
being rolled into the wire. — D. H.
Copper, Modulus of Elasticity of Electrolytic. — Tests have been
undertaken by B. Welbourn J to ascertain the modulus of elasticity,
* Physical Review, 1917, vol. x. p. 601.
t Proceedings of the American Society for Testing Materials, 1917, vol. xvii. p. 116,
X The Metal Industry, 1918, No. 4, vol. xii. p. 70.
238 Abstracts of Papers
under working conditions, of a number of stranded cables of hard-
drawn electrolytic copper wire. The tests were made on an experi-
mental span of about 150 ft., and special precautions were taken to
prevent movement or bending of the posts of suspension. The
following sizes of conductors were tested :
7 strands of 0068 in. bare hard-drawn copper strand
7 „ 0-097 „
19 „ 0083 „ „ ,
37 „ 0092 „
As a result of his experiments the author gives the following as
suitable working figures for the modulus of elasticity :
7 strand cable .... 20,000,000 lb. per sq. in.
19 „ .... 17,500,000 „ „
37 , 15,500,000 „ „
and he suggests a value of 20 x 10-^ as a suitable working figure for
sohd wire. — D. H.
Crystal Analysis by X-Rays. — The ordinary method of examining
crystals by means of X-rays requiring well-formed crystals, A. W.
Hull * has devised a method which makes use of fine powders. The
metal or other substance must be in such a fine state of division that
the distribution of crystal planes within it may be considered as a
quite random one, and the uniformity is rendered greater by rotating
the specimen, enclosed in a glass tube, throughout the exposure.
Very long exposures, from ten to twenty hours, are necessary, using
a tungsten or molybdenum target. In order to secure monochromatic
radiation, a filter is used, consisting of powdered zircon for a molyb-
denum target, or of metallic tungsten for one of tungsten. A separate
band is produced by each definite crystalhne plane, provided that the
distance between the planes is at least half a wave-length.
Iron has a centred cubic lattice, and silicon steel with 3 "5 per cent,
of silicon shows no change either in arrangement or intensity of the
lines. Experiments in liquid air, at room temperature, and at 1000° C.
showed no differences, but the high temperature experiments were
unsatisfactory, and it is not yet certain whether allotropy in iron
may be detected by this means.
Sodium, aluminium, and probably also lithium, have the face-
centred cubic lattice, hke gold and silver. Nickel resembles iron.
Magnesium gives a pattern which is hexagonal with slight distortion,
probably attributable to a slight asymmetry of the atoms. Sihcon
has a lattice of the diamond type, consisting of two interlacing face-
centred lattices, one of which is displaced along a cube diagonal of
the other by one-fourth of the length of the diagonal. Graphite has a
complex structure, the natural and artificial varieties giving identical
results. The structure is hexagonal, and is composed of four simple
♦ Physical Review, 1917, vol. x. p. 661.
Properties of Metals and Alloys 239
lattices of triangular prisms. Tliis is the lowest symmetry of any
elementary substance yet studied. The diamond gives results com-
pletely identical with those obtained by Bragg with perfect crystals.
Practical difficulties arise in certain cases from the high proportion
of amorphous material present in finely divided metals, such material
naturally giving no pattern. — C. H. D.
Crystals, Production of. — Crystals of several metals have been
obtained in gelatinous silica by H. N. Holmes.* By adding gold
chloride to a siUca jelly and allowing it to set, and then covering with
oxahc acid solution, good crystals of gold appear in a few hours. With
a denser jelly coloured bands of colloidal gold are obtained. In the
same way copper sulphate and hydroxylamine hydrochloride yield
fine tetrahedra of copper. Many salts also crystalHze well under
such conditions. As the crystals of salts are also obtained by using
fine powders, such as sihca, alumina, or sulphur, in place of a jelly,
the result is attributed to the capillary structure of the gelatinous
mass. — C. H. D.
Emulsions and Suspensions with Molten Metals. — H. W. Gillett,t
in a paper read before the American Chemical Society, suggests that
molten metals from mercury to tungsten and their alloys offer their
problems to the colloid chemist.
A number of practical instances are quoted. The failure to coalesce
of globules of aluminium when melting aluminium chips from the
machine-shops, which frequently contain 5 to 15 per cent, of cutting oil
or compound, and 5 to 15 per cent, of very fine dirt. The very fine chips
are the chief source of loss, these forming minute globules which are
too light specifically to enable them to break through their surrounding
coat of oxide and coalesce with other globules. The practical methods
of promoting coalescence by " puddling " or by the use of flux such as
sodium chloride and fluorspar are described.
Other instances of emulsions given are " floured " or " sickened "
mercury, blue powder in zinc smelting, oxidized fusible boiler plugs,
entangled oxides in brass, bronze, and aluminium ; metal globules in
slags ; metal fog in the electrolysis of fused salts {e.g. of strontium and
cerium) ; zinc dust in sherardizing ; aluminium powder and alumina
in calorizing (to prevent the welding together of clean metal surfaces) ;
molten alloys of copper and lead.
The suggestion is made that stable emulsions of metals normally
immiscible in the liquid state would be industrially useful, as also
emulsions of gases with metals, if uniformly porous. — F. J.
Fused Metals, Thermo-Electric Properties of. — Further determina-
tions of the thermo-electric properties of fused metals have been made
* Journal of Physical Chemistry, 1917, vol. 21, p. 709.
t Journal of Industrial and Engineering Chemistry, Jan. 1917, vol. ix. p. 31.
240 Abstracts of Papers
by C. K. Darling and A. W. Grace,* the apparatus being so arranged
that one part of a column of metal is solid and another liquid, metallic
contact being made with each part. No abrupt change occurs on
fusion in the case of lead, tin, cadmium, zinc, or aluminium. The
thermo-electric power of a nickel-brass-lead couple varies in a linear
manner with the temperature above the melting point.
Antimony, hke bismuth, shows an abrupt change at the melting
point. This may be due to an allotropic change. The ordinary thermo-
electric diagram, given in most text-books, is of no value. — C. H. D.
Gold and Platinum, Colloidal. — The effect of plates of different
metals on the precipitation of colloidal gold and platinum has been
studied by E. B. Spear and K. D. Kahn.f Pohshed plates of equal
size are placed in equal volumes of the colloidal solutions, and the
time required to produce coagulation is noted. The order of activity
proves to be, for the metals examined, zinc-steel-nickel-tin-copper.
Roughened surfaces are much more active than smooth. It appears
that the cause of the precipitation is the dissolving of some of the
metal, forming positively charged ions, which then neutrahze the
negative charge of the colloidal particles. Since copper does not
dissolve in water in the absence of oxj^gen, it is found that copper is
without effect when an atmosphere of hydrogen is used. The presence
of copper in the coagulated colloid has been proved analytically. —
C. H. D.
Grain Size of Metals. — The value of grain-size deternaination for
the purpose of predicting or interpreting the physical properties of
metals is discussed, and the more important methods of measurement
outlined by Zay Jeffries.;!: According to the theory conceived by
Beilby and so ably championed by Rosenhain, Humtrey, and others,
a metal is built up of cr}'stals bound together by a cement of amorphous
material. The physical properties should vary with changes in the
proportion of amorphous material present. In metal in the annealed
or unstrained state the cement is situated between the boundaries of
the crystals. The coarser the structure the fewer the boundaries in a
given volume and the less amorphous material present. In this case,
therefore, grain-size measurement would seem to offer the best method
of determining the relative amounts of crystaUine and amorphous
material present for the purpose of the control of physical
properties.
W. Rosenhain has pointed out that coarseness of structure may
only shghtly impair the tensile strength and ductility of a metal.
Under shock and fatigue tests, however, a coarse structure gives
unsatisfactory results.
♦ Proceedings of the Physical Society, 1917, vol. xxx. p. 14.
t Joumalof the American Chemical Society 1918, vol. ad. p. 181.
i Faraday Society Transactions, June 1917, vol. xii. pp. 40-53.
Properties of Metals and Alloys 241
Grain size, therefore, may prove to be a better indication of the
behaviour of a metal in service than the tensile test. C. H. Mathewson
and P. Phillips have found it more sensitive than the tensile test in
determining the mechanical properties of a-brass.
The following results by the above authors, on two samples of
annealed a^brass, are given : '
Brass containing copper 66-56, lead 0-26, iron 0-08 per cent.
Properties after half-hour anneal at 550° C.
1
Initial
Reduction,
per Cent.
Elongation
on 1 in. per
Cent.
Reduction of
Area, per Cent.
Ultimate
Strength, Lbs.
per Sq. In.
Scleroscope
Hardness.
Grains per Sq.
In. at 85
Diameters.
20
50
72
73
59-5
620
46,739
47,100
10
10
55-5
67-2
Fahrenwald has found variations in Brinell hardness of gold from
23-8 in coarse to 94-7 in fine-grained metal.
It is probable that grain-size measurement would throw light
on certain corrosion problems. In connection with the presence of
amorphous material, L. Aitchison has stated: "Whichever or what-
ever explanation be accepted as the cause of this amorphous layer,
its presence can hardly be doubted and its influence upon corrosion
cannot be neglected."
In connection with the interpretation of results it is pointed out
that the grains resulting from anneahng and recrystallization of cold
worked metal are usually longer in the direction of original deforma-
tion. It is difficult in some cases to tell whether this persistent
^elongation of the grains is the result of moderate cold work without
aimealing or severe cold work followed by annealing. The specimen
usually furnishes a clue, however. In the former case elongation of
the individual grains will be greater in the neighbourhood of the
points of apphcation of the stresses, e.g. near the surface in rolled,
drawn, or hammered metal. In the latter condition this difference
is not marked.
H. Baucke finds that in copper annealed after severe cold work
the resulting recrystalhzed grains are longer in the direction of de-
formation until an annealing temperature of 900° C. is reached. Above
900° C. the resulting grains are longer in a perpendicular direction.
The author's experience indicates that such a condition is not general,
and that there is a great tendency for recrystallized grains to have
their longer dimension in the direction of deformation even after a
long sojourn at relatively high temperatures.
Metals which have been cold worked and subsequently annealed
a.t temperatures]^well above that of recrj^stallization are apt to have
very even grain size (Robin).
VOL. XIX. E.
242 Abstracts of Papers
It is urged that the full value of grain size determination can only
be realized after due correlation with the physical properties and
behaviour of metals in service.
A bibliography is appended. — S. L. A.
Lead Standard Electrode. — It has been found that cells made up
with lead amalgams may be made to give a constant E.M.F. W. E.
Henderson and G. Stegeman * prepare the amalgams by the electro-
lysis of a 10 per cent, solution of lead nitrate, using a mercury cathode
and a platinum anode, until the amalgam contains from 2-5 to 6 per
cent, of lead. An H form of cell is used, and the amalgam is kept
in contact with lead sulphate mixed with sodium sulphate crystals.
The other electrode is of mercury, covered with a mixture of meicurous
sulphate and sodium sulphate. A saturated solution of sodium
sulphate and lead sulphate is used as filling liquid. The electromotive
force of this cell is given by the equation
Et = 0-96463 + 0-000174 (t - 25) + 0-00000038 (< - 25)»
By using a similar cell, but with an electrode of freshly deposited
lead in place of the amalgam, the potential of lead against an iV/10
calomel electrode is found to be 04696 at 25° C— C. H. D.
Liquid Metals, Vapour Pressure of. — The known vapour pressures
of liquid metals have been compared by J. H. Hildebrand,f using
a rule that the heat of vaporization divided by the temperature of
vaporization on the absolute scale is the same for all normal liquids,
provided that the comparison is made at temperatures at which the
saturated vapours have the same concentration. This differs from
Trouton's rule in regard to the temperature chosen. A constant a
then expresses the ratio of the absolute temperatures at which two
liqmds give vapours of the same concentration.
Taking mercury as the standard, and using the best experimental
results available, the following values of a are obtained :
Mercury ....... 1-00
Cadmium 1-74-1-77
Zinc 2-00-2-04
Thallium 2-75
Lead 3-30
SUver 4-30
The general vapour pressure equation becomes:
log p = - 3140a/T +7-85 + log a,
where p is measured in millimetres of mercury.
* Journal of tht American Chemical Societi/, 1918, vol. xl. p. 84.
t Ibid., vol. xl. p. 45.
Properties of Metals and Alloys
24&
The following values of a have been calculated for metals of wliich
the experimental data are doubtful, working from this equation :
Magneaium
Bismuth .
Antimony
Aluminium
Manganese
Chromium
Tin
Copper .
Nickel
Iron
2-37
2-93
300
3-65
3-86
4-40
4-60
4-66
4-80
4-90
These values may be used for the calculation of the heat of vaporiza-
tion, and of the volatiUty at any temperature. — C. H. D.
Metals, X-Ray Examination of. — The soundness of autogenous welds
in iron and aluminium has been examined by H. Pilon,* by means
of a Coolidge tube. The author shows photographs and radiographs
of a normal weld, and then compares them with similar photographs
obtained during the examination of unsound and oxidized welds.
Advantage is taken of the selective action of different metals in filtering
X-rays, to use this method of examination for disclosing the presence
of pieces of iron and lead in a block of aluminium, and the radiographs
given in the paper indicate very clearly the presence of these foreign
bodies. — D. H.
Nickel, Colloidal. — Colloidal nickel may be prepared, according
to C. Kelber,f by reducing a solution of nickel formate and gelatine in
glycerine at 200° C. by passing a current of hydrogen. The solution
becomes deep brown, and is stable in air. It is not precipitated by
mixing with alcohol. If mixed with water and centrifuged, the metal
is thrown out as a dark brown mass, which can again yield colloidal
solutions with acidified water, acetic acid, alcohol, or glycerine.
In place of gaseous hydrogen, such reducing agents as hydrazine,
hydroxylamine, formaldehyde, or hypophosphorous acid may be used
at the same temperature, whilst the gelatine may be replaced by gum-
arabic, and the nickel formate by the acetate or by freshly precipitated
nickel hydroxide. — C. H. D.
Nickel, Electrolytic Behaviour of. — Measurements by A. Smits and
C. A. Lobry de Bruyn J show that the equiUbrium potential for nickel
is —0*480 volt with respect to the normal calomel electrode, but that
this undisturbed value is only obtained in an atmosphere free from
hydrogen or oxygen or in a vacuum, or when a solution of a nickel salt
is used in which the concentration of hydrogen ions is less than one-
thousandth of that of the nickel ions. In all other measurements
the potential measured is not that of undisturbed nickel. — C. H. D.
* Revue de MUailurgie, 1916, vol. i. p. 1.
t Berichte der deutschen chemischen Qesellschajl, 1917, vol. 1. p. 1509.
X Proceedings o/the Royal Academy of Sciences, Amsterdam, 1918, vol. sx. p. 394.
244 Abstracts of Papers
Photo-Electric Effect. — A further study of the photo-electric effect
has been made by A. L. Hughes.* Using the alloy of sodium and
potassium wliich has been so frequently used in these investigations, it is
found that the selective and normal photo-electrons difier rather in their
distribution as regards direction than as regards velocity. — C. H. D.
Physico-Chemical Data for Metallurgists. — ^In a paper presented
to the American Chemical Society, J. W. Richards f emphasizes the
need for research by physical chemists in order to supply the metal-
lurgist with important thermo-chemical data relating to metallurgical
reactions at high temperatures. Directions in which thermo-chemical
data are deficient or lacking are : combinations of metallic oxides
with silica, forming siUcate slags, of metallic sulphides with each other,
forming mattes, of metallic arsenides forming speisses, of metals with
each other forming alloys, &c. &c. Available thermo-chemical data
are not exact for high temperatures, at which the energy involved in
a reaction is different from what it is at room temperature. The
author quotes as an example the reduction of liquid silica at 1800°
C. to liquid silicon and CO gas ; tabulated heats of formation apply
only to a temperature of 15° to 20° C. and not to the equation under
the actual conditions of the reaction.
Specific heat curves are required wliich will give the specific heats
from 0° to melting point, and from melting point to boiling point, and
also above boihng point.
Latent heats of fusion for irons, steels, brass, and bronze are urgently
needed, also latent heats of vaporization. For instance, the latent
heat of vaporization of zinc represents probably 25 per cent, of the
net thermal work done in a zinc retort.
The vapour tensions of metals and metallic compounds at various
temperatures are also required. Nearly all metals lose weight in being
melted, e.g. in producing silicon 25 per cent, is lost by vaporization ;
silver readily evaporates before it melts.
The example of zinc is given to illustrate the data that should be
similarly available for all important metals, alloys, and compounds :
Heat content solid to 0° C. : 0-0906f + 0-000044^.
Heat in solid at melting point : 45-2 calories.
Latent heat of fusion : 22-6 calories.
Heat in liquid at melting point : 67-8 calories.
Specific heat liquid : 0-179 (not determined for all temperatures).
Heat in liquid at boiling point : 605 calories.
Specific heat of gas per kg. : 0-077 (estimated on theoretical grounds).
Vapour tension, liquid: log p (mm.) = 6365/T + 8-17 (deduced from Barns' observa-
tions).
Vapour tension at melting point: 0-093 mm. mercury.
Vapour tension, solid : log p (mm.) = — 6685/T + 8-63.
Vapour tension at 0° C : 1 -)-10-i« mm. mercury.
In the case of brass and bronze, we know only the specific heats
♦ Physical Review, 1917, vol. x. p. 490.
t Journal of Induslriai and Engineering Chemistry, November 1917, vol. ix. p. 1056.
Properties of Metals and Alloys 245
from 100° to 0° and the total heat content at the melting point for
only one variety of each. — F. J.
Quenching o£ various Metals in Water. — Mm. Garvin and Porte vin *
have studied the rates of cooUng of samples of various metals — pui-e
silver, aluminium, nickel, and 30 per cent, nickel steel — dming the
operation of water quenching. The determinations were made with
a special dead beat galvanometer, used in conjunction with a photo-
graphic recorder, the temperatures being measured by means of a
platinum-platinmn-iridium thermocouple placed at the centre of
the specimen. It was found that the nature of the contact between
thermocouple and specimen was of great importance, and in order
to ensm'e that this contact was always identical, the device was adopted
of welding the ends of the two wires together to form a bead, which
was then sectioned through the middle. The contact was then made
by allowing the couple to rest on the specimen under its own weight,
and the constancy of this contact was checked during the experiments
by the measm'ement of its electrical resistance. The quenching was
carried out by a current of water ascending at the rate of 01 Htre per
second. Good agreement between the cm-ves was obtained in the
case of those specimens which were quenched the least rapidly, but
difierences were obtained in other cases. The authors attribute these
to difierences in the sm'face conditions of the specimens. They do
not find it possible to represent these curves accurately by a mathe-
matical formula such as that suggested by McCance, except in the
case of specimens of similar diameters, if they are of the same metal,
and for those of similar physical properties if they are of different
metals. They conclude that it is preferable to make use of curves
determined by experiment rather than those obtained from formulae
estabhshed by theoretical reasoning. — D. H.
Silver, Action o£ Chromic Acid on. — Some abnormalities having
been found in previous work on the velocity of solution of silver in
acid solutions containing chromic acid, this case has been investigated
by R. G. Van Name and D. U. Hill.f It is found that the chief cause
of variation is the physical state of the metal. The outer layer of
cold-rolled sheet silver shows a higher velocity of solution than the
inner mass of the metal. The initial irregularities may be removed
by a preliminary treatment with nitric acid. No such difierences of
velocity have been observed in the case of cadmium. — C. H. D.
Sodium, Preparation of. — A simple preparation of metallic sodium
as a lecture experiment is described by S. Wiechowski.J A stick
of sodium hydroxide is grooved along its length and laid in a glass
* Revue de Mitallurgie, 1917, vol. v. p. 604.
t Chemiker-Zeitung, 1917, vol. xli. p. 739.
j American Journal of Science, 1918 (iv.), vol. xlv. p. 54.
246 Abstracts of Papers
trough, electric contact being made with its two ends by knitting
needles pressed down into the ends of the groove. The stick is left
exposed to air sufficiently long for it to become moist, and is then
covered with paraffin oil. When the needles are connected with the
lighting circuit electrolysis takes place, and metaUic sodium is formed
at the cathode. — C. H. D.
Solid Solutions, Properties o£. — Attention is drawn to the remark-
able similarity in physical properties between soUd solutions and hard-
worked metal by F. C. Thompson.* It is considered that this close
similarity in characteristic properties justifies the assumption that
the same cause, namely, [distortion of the crystals, is operating in
each.
In the case of solid solutions the distortion is explained on the
theory that the process of crystallization causes an equahzation of the
atomic volumes of the constituents. Elastic stresses are thus set up
which, by increasing the resistance to further stresses, raise the hardness
of the mass. On this theory the relationship between hardness and
concentration are expressed by a parabolic curve wliich corresponds
absolutely with those observed for simple solid solutions, such as the
gold-silver alloys. The hardness and fragiUty of intermetallic com-
pounds are also explained by the theory.
In the discussion C. H. Desch questioned whether the increase of
hardness which occurred on alloying gold and silver could yet be
understood, the atomic volumes were practically equal, the space
lattices were almost certainly identical. F. C. Thompson pointed out
that it had been shown in the paper that even the slight difference
in atomic volume between gold and silver was quite sufficient to
explain the hardening produced by their solution, if it be granted
that the two metals in crystalUzing together are compelled to conform
to an identical mean atomic volume. — S. L. A.
Thermo-Electric Effects. — ^It has been shown by C. Benedicks f
that an asymmetrical distribution of temperature in a homogeneous-
metal gives rise to an electromotive force. A copper cable is unwound
for a short distance at each end, the wires spread out, and attached to
two large copper plates, but insulated from them by mica. On con-
necting the two plates with a galvanometer, and heating one of them,
a current passes from the cold to the hot end. Effects are also obtained
when a thin annealed platinum wire is connected with the galvano-
meter and then cut in the middle. Heating one end and pressing
it on to the cold end produces a marked deviation. Tungsten, and
especially ferro-siUcon, gives much larger deviations.
The same author f has also observed the effect in thin sheets of
♦ Faraday Society TransacUone, June 1917, vol. xli. pp. 23-29.
t Comptee rendus, 1917, vol. clxv. p. 391.
J Ibid., p. 426.
Properties of Metals and Alloys 247
liqiiid mercury, although only indirectly, by determining the magnetic
efEect.— C. H. D.
Titanium, Metallurgy of. — In a thesis presented to the Case School
of Applied Science, R. J. Anderson * discusses various aspects of the
metallurgy of titanium. After giving an account of the history of
the metal, the author proceeds to describe the physical and chemical
properties, the methods of preparation, and the geology and mineralogy
of this element. Titanium is a silvery -white metal, with a steely frac-
ture. From a metallurgical standpoint one of its most interesting
properties is its workability ; when cold it is brittle, but at a red heat
it may be readily forged and drawn. Pure titanium is not used to any
extent on account of its high melting point. Metalhc alloys, such as
ferro-titanium and cupro-titanimn, are employed. Cupro-titanium is
manufactured by the reduction of rutile in a bath of aluminium, to
which copper has been added for the purpose of alloying with the
reduced titanium. The alloy is costly, and has not yet been exploited
in the commercial field to any degree. Mangano -titanium is an alloy
introduced by the Goldschmidt interests, for use as a deoxidizer of
brass. It contains 30 to 35 per cent, titanium. Titanium has been
employed in the filaments of incandescent lamps, but its use is hindered
by technical diflSculties connected with the manufacture of the wire.
The main use for titanium at present is as an addition to liquid
steel as a final deoxidizer and remover of nitrogen before casting. — ^D. H.
Tungsten, Expansion of. — The expansion of tungsten with heat has
been determined by A. Gr. Worthing,! using horizontal filaments,
stretched by means of a weight, for temperatures below incandescence,
and vertical filaments enclosed in tubular bulbs for higher temperatures.
The values obtained at 27° C, 1027°, and 2027° respectively are 4-44 X
10-«, 5-19 X 10-«, and 7-26 X lO"". Tungsten has the lowest coefficient
of expansion of any known element except the diamond within the
range of ordinary temperatures. Molybdenum may possibly have a
still lower expansion. — C. H. D.
Tungsten, Space-Lattice of. — Powdered tungsten has been examined
by the X-ray method by P. Debye.J The absorption of the rays by
the metal is very strong, but good interference figures have been
obtained, which indicate that the unit of the space-lattice is the centred
cube, and that the length of the edge of a unit cube is 3"18 X 10"* cm. —
C. H. D.
Vapour Pressure and Volatility of Several High Boiling Point
Metals. — ^In a review of the work which has been done in connection
with determinations of vapour pressures of metals at different tempera*
• Journal of the Franklin Institute, 1917, vol. 184 (4), p. 469.
t Physical Beview, 1917, vol. x. p. 638.
f Physikaliache Zeitschrift, 1917, vol. xviii. p. 483.
24S Abstracts of Papers
tures, J. Johnston * summarizes the work of Barus, Greenwood,
Berthelot, Hey cock, and Lamplugh, Von Wartenberg, Langmuir and
Mackay, Egerton, Demarcay, KrafEt and Bergfeld, Tiede and Fischer,
Berry, T. Turner, and his collaborators.
Some work on the volatilization of metals at atmospheric pressure
has been done, e.g. that by Bengough and Hudson, Bassett, Rose. .
Butts has discussed the vaporization of copper in wire-bar furnaces,
and indicates that this occurs to an appreciable extent at 1120° C.
Mostowitsch and Pletneff state that gold is not appreciably volatile
at 1400° C. in an atmosphere of oxygen, nitrogen, carbon monoxide, or
carbon dioxide, but volatility is noticeable in hydrogen at 1250° C.
An explanation is offered of the results obtained by Groves and
Turner, and Thorney croft and Turner, who found that some iron or
copper came over with zinc when the respective binary alloys were
distilled under certain circumstances, the temperature, however, corre-
sponding to a very small vapour pressure of the less volatile metal.
The author suggests two alternative explanations, viz. (1)
That the particles of vapour of the less volatile metal are entrained by
the blast of zinc vapour, just as the gas from the vessel to be exhausted
is entrained by the blast of mercury vapour in the condensation pump ;
(2) that when all the zinc particles surrounding a given iron (or copper)
particle have vaporized, the iron particle is left unattached, and so is
carried over into the distillate. The author admits the possibihty
that the compound of zinc with copper or iron may have an appreci-
able vapour pressure and distil as such. — F. J. ^
X-Rays and Crystal Structure. — An important series of papers,
discussing the whole problem of crystal structure in the hght of Bragg 's
work, has recently been pubhshed in Russian. As no translation is
available, the summary by T. V. Barker, f in which the subject is
critically reviewed, may be mentioned. Silver, gold, copper, and lead
are now all known to have the face-centred cubic lattice. — C. H. D.
X-Rays, Emission oL — The intensity of emission of X-rays by
metals has been determined by C. S. Brainin | for the cases of platinum,
tungsten, silver, molybdenum, copper, and cobalt, over a range of
from 5000 to 33,000 volts. The equation derived from the results
of previous workers is ^^ = KAP^, where E is the intensity, K a
constant, A the atomic weight of the radiating metal, and P the
difference of potential between the electrodes of the tube. The results
are different for different metals. For platinum and tungsten the
law is only obeyed above the critical voltage, whilst molybdenum
obeys it strictly throughout the whole range. Copper and cobalt
obey the law below the critical voltages, above which the emission
• Journal of Industrial and Engineering Chemistry, September 1917, vol. ix. p. 873.
t Ghemical Society Anniial Reports, 1917, Vol. xiv. p. 226.
J Physical Review, 1917, vol. x. p. 461.
Properties of Metals and Alloys 249
increases too rapidly, whilst silver is similar, except tliat above the
Umit the increase is less rapid than corresponds with the law. — C H. D.
Zinc, Electrolytic. — W. N. Ingalls * gives an account of the electro-
metallurgy of zinc. The process is by no means a new one. Electro-
lytic refining was attempted on a large scale by Nahnsen, in Silesia,
in the 'nineties, and hydrometallurgical-electrometallurgical treatment
of zinc ore was attempted disastrously by Ashcroft, at Cockle Creek,
N.S.W., in a works costing a milUon dollars. Dr. Hoepfner developed
a process which was put into use at Ruhrfort on the Rhine, and at
the large works of Brunner, Mond & Co., in England. At the former
it was abandoned after a short time, but at the latter it has been in
operation for a long period, producing a few hundred tons of spelter
annually.
In 1915 the production of electrolytic zinc direct from the ore was
inaugurated on a large experimental or even commercial scale at
several places, the most important being at Anaconda, Mont., where
the total output was about 5 tons a day. In this process the ore is
concentrated to give as high a zinc content as possible, after which
it is roasted to produce a calcine containing about 2 to 3 per cent,
of sulphur, mainly as sulphate. The temperature must be kept below
730° C. in order to prevent the formation of insoluble zinc ferrite.
The calcine is treated with sulphuric acid, which dissolves the zino
and a little iron ; a small amount of manganese dioxide is added to
oxidize the iron, which is then precipitated by the addition of a Uttle
limestone. Arsenic and antimony are carried down with the pre-
cipitate, and a little zinc is then added to the solution to remove
copper and cadmium, the hquid is filtered and run into the electrolytic
cells, where the zinc is deposited on aluminium plates, which are
stripped every twenty-four hours. The anodes of the cells are of
pure lead, and the solution is electrolyzed at a current density of 20
to 30 amperes per square foot of cathode surface. Apart from the
Anaconda work, the most ambitious plans carried on in 1915 were
those of the Consolidated Mining and Smelting Company, of Canada,
while electrolytic zinc was also produced by the Electro Zinc Co., of
Welland, Ont. The work at Welland is unique in that the solution
of the zinc and the electrolysis are both carried out in the same vat,
the cathode being enclosed in a canvas bag.
The production of high-grade electrolytic zinc is not difl&cult.
Lead ought not to go appreciably into solution at all, while iron, copper,
and cadmium, the other common impurities of spelter, are readily
precipitated. The purity should be not less than 99 9 per cent., and
indeed Brunner, Mond & Co. have for many years guaranteed their
electrolytic spelter at 99 95 per cent. The author does not consider
that the electrolytic method of manufacture will supplant the older
methods of extraction. — D. H.
* The Metal Industry, 1917. vol. xi. (16), p. 345.
250 Abstracts of Papers
11.— PROPERTIES OF ALLOYS.
Acid-Resisting Alloys. — Some notes on the high-silicon iron alloys
now used for acid plant are given by S. J. Tungay.* The siUcon
must not be less than 12 per cent., whilst from 20 per cent, upwards
the resistance to acids again falls. The shrinkage during cooUng,
and the hardness and brittleness of the alloys, are serious diflSiculties
in the manufactm*e of plant. The separation of graphite also causes
trouble.— C. H. D.
Aluminium-Bronze. — W. M. Corse and G. F. Comstock f present
results of tension and endurance tests with the Landgraf-Turner and
White-Souther machines, made on manganese-bronze and aluminium-
bronze, showing that although the former alloy may give better figures
when tested in tension, the latter is far superior in endurance of alter-
nating stresses. A few alternating stress tests on phosphor-bronze,
malleable cast iron, and rail steel are cited in comparison. The signi-
ficance of the alternating stress tests is explained, and the proper
method of reporting results by cm'ves is described by quoting from
Kosenhain's book on " Physical Metallurgy." Carpenter and
Edwards' Eighth Eeport to the Alloys Eesearch Committee is also
quoted as checking and explaining the combination, in aluminium-
bronze, of low yield point in tension with great endurance of alternating
stresses.
A method of heat treatment is explained and described in detail,
by means of which the proportionality hmit of 10 per cent, aluminium-
bronze was raised very substantially without the loss of too much
ductiUty. It was shown that this method is applicable to castings
of ordinary size, as well as to small test specimens, and that it increases
the endurance under alternating stresses as well as the proportionality
limit intension. — D. H.
Aluminium-Bronze, Hardening of. — An article which appeared in
the Giesserei Zeitung for June 1, 1917, is summarized. J It is shown
that higher grade alloys (more aluminium than 7 per cent.) can be
hardened by thermal treatment and by the further addition of iron,
sihcon, and other elements, the mechanical properties of the alloys
can be much varied.
Thus bronzes can be prepared having a Brinell hardness of 100
without being brittle. An aluminium -bronze resembhng in its mechani-
cal properties a 0 35 carbon steel was given hardness values ranging
• Juurnalof the Society of Chemical Industry, 1918, vol. xxxvii. p. 87.
t Proceedings of the American Society for Testing Materiale, 1916, vol. xvl. p. 118.
X Journal of Industrial and Engineering Chemistry, Dec. 1917, vol. ix. p. 1144.
Properties of Metals and Alloys
251
from 100 to 260 by various thermal treatments ; such bronzes of great
hardness will answer as bearing metals even for high speeds.
The following figures are given as to the properties of a 10 per cent,
aluminium-bronze containing some titanium, the percentage of which
is not quoted :
'
Bronze
as Cast.
Quenched
Bronzg
After Thermal Treat.
ment at Different j
Temperatures. 1
Limit of elasticity ....
Tensile strength ....
Elongation per cent.
Contraction of area per cent.
Brinell hardness ....
Kg. per Cm.2
9-6
51-8
19-5
33-7
100
Kg. per Cm.2
19-8
73-6
10
0-8
262
Kg. per Cm.2
27-7 to 19-2
67-7 „ 64
5-5 „ 14
9 „ 18-6
158 „ 140
—F.J.
Aluminium Selenides. — The behaviour of mixtures of aluminium
and selenium has been examined by M. Chikashige and T. Aoki.*
Combination takes place explosively, so that only small quantities
can be taken for the cooling curves. The freezing-point cmve is of
simple type, there being a single compound, AljSe^, melting at 950°
and forming a rather flat maximum. Sohd solutions are not formed,
and the two eutectics are practically indistinguishable from the pm'e
components. The compound is brown and soft, and has a much
greater density than aluminium, so that the crystals as they are formed
sink to the bottom of the crucible, and the regulus after solidification
has the appearance of consisting of two layers. The selenide is decom-
posed by moist air, yielding hydrogen selenide. — C. H. D.
Aluminium Tellurides. — Aluminium is stated by M. Chikashige
and J. Nose f to combine explosively with tellurium, so that alloys
must be prepared by melting the tellurium and adding very small
successive quantities of aluminium, a slight explosion taking place
on each addition. An atmosphere of hydrogen is used. Two com-
pounds are formed, one of which, TcgAl, is stable and appears as a
pronounced maximum on the freezing-point curve at 895°. This
compound can take up to 44 per cent, of telluiium into solid solution.
The eutectic points are at 2 8 and 97 per cent, of aluminium, and at
414° and 621° respectively. Alloys which contain the second eutectic
undergo a transformation at 551° on cooling, a second compound,
TeAl5, being formed. This does not enter into sohd solution. All the
alloys are readily decomposed by moisture, evolving hydrogen telluride,
which then deposits tellurium, so that sections must be ground and
pohshed in oil. — C. H. D.
♦ Memoirs of the College of Science, Kyoto, 1917, vol. ii. p. 249.
t Ibid., vol. ii. p. 227.
••25-2 Abstracts of Papers
Antimony Selenide. — Antimony combines with selenium, according
to M. Chikashige and M. Fujita,* to form a single compound, Sb^Sg,
which has a maximum freezing point of 572°. The curve falls very
steeply on the antimony side to a eutectic point at 497° and 46 '5 per
cent, of selenium. On the selenium side it falls, with a double inflec-
tion, to the freezing point of selenium. Solid solutions are not formed.
The compound crystalUzes in needles, and only tarnishes slowly in air,
at last becoming covered with a black powder. — C. H. D.
Cadmium Selenide. — Cadmium and selenium, according to M.
Chikashige and R. Hitosaka,f form two immiscible liquid layers.
On heating above 360° C, combination takes place to the selenide,
CdSe, which does not melt even at 1350°. This is a grey compound,
insoluble in the melt, and may be obtained pure by heating the mix-
tures sufficiently to volatihze the excess of cadmium and selenium.
It has a specific gravity of 5-81. — C. H. D.
Dental Amalgam as an Absorbent £or Mercury. — The tin-cadmium
alloy used for dental purposes has been found by L. A. Welo J to be
effectual in absorbing mercury in place of gold leaf, when it is necessary
to prevent the passage of vapour from a mercury pump to a vessel
which is being exhausted. The alloy, consisting of two parts of tin
to one of cadmium, is used in the form of milUngs, and a column of
not more than 50 cm. is required for complete absorption. — C. H. D.
Heat Treatment o£ 10 per Cent. Aluminium-Copper. — The efiect
of varying thermal treatment on the mechanical and micrographic
properties of two aluminium-copper alloys has been investigated by
Portevin and Arnou.§ The alloys chosen contained 10 per cent, of
aluminium with and without the addition of 1 per cent, of manganese.
On each alloy the following variations of treatment were adopted :
1. Quenching at different temperatures after a fixed period at that
temperature.
2. Annealing at various temperatures after quenching at 800° C
3. AnneaUng at various temperatures after quenching at 900° C.
After each of these treatments the alloys were submitted to tensile,
impact, hardness, and shock tests, and to microscopic examination.
In both alloys it is found that quenching temperatures up to 500° C.
have no effect on the mechanical properties. When, however, the
temperature of the eutectoid, 550° to 600° C, isexceeded, the mechanical
properties are functions of the quenching temperature until 900° C. is
reached, a result which is in agreement with the equilibrium diagram.
Quenching at temperatures of 600° C. and 700° C. gives an increased
♦ Memoirs of the GoUege of Science, Kyoto, 1917, vol. ii. p. 233.
t Ibid., vol. ii. p. 239.
t Physical Review, 1917, vol. x. p. 583.
§ Revue de Mitallurgie, Mar. 1916, vol. xiii. (2), p. 101.
Properties of Metals and Alloys , 253
value to all the characteristic mechanical properties ; above this
temperature the tensile strength and hardness increase rapidly, but
the elongation and resistance to impact decrease.
The first efiect of reheating the quenched alloys is to increase the
tensile strength and hardness, and to reduce still further the elongation
and resistance to impact. This effect lasts up to an anneahng temper-
ature of 400° C, after which the strength and hardness decrease rapidly,
while the elongation and resistance to impact increase. This rapid
variation in properties with increasing anneahng temperature is
especially marked in the alloy which contains 1 per cent, of manganese,
as is also the general improvement in the mechanical properties of
both of the alloys after this double treatment compared with those
of the original rolled material. For example, in the case of the alloy
containing 1 per cent, of manganese, quenching at 900° C, followed
by annealing at 600° to 700° C,, gives a product over 20 per cent,
stronger than the original material, while the elongation is increased
200 per cent, and the resistance to impact over 400 per cent. In all
cases a quenching temperature of 800° C. gives improved results
over one of 800° C, but the general character is the same in both
cases.
Micrographically the alloys normally consist of two soUd solutions,
a and y. Above the eutectoid point, between 550° and 600° C, these
constituents combine to form ^, which combination only becomes
complete at 900° C. On quenching the yS solid solution, it assumes
an acicular, " martensitic " structure, similar to that met with in
steels, and this constituent is relatively hard and brittle. On annealing
this p solution deposits a and y sohd solutions, but in a much finer
and more intimately mixed condition than is ever found in the com-
pletely annealed alloy, and the improvement in properties is attribut-
able to this intimacy of mixture of these two constituents. Annealing
at 800° C. is less effective in producing improved results, because the
formation of the /S constituent, which is a necessary preliminary
to the refinement, is incomplete at that temperature. — D. H.
Inspection o£ Brass and Bronze. — Extensive failures of wrought
60 : 40 brasses, especially when the alloy was used in the form of
bolts, rods, and sheet, have led A. D. FUnn and E. Jonson * to investi-
gate the conditions which led to these failures, and to suggest methods
by which they might be prevented.
The failures, which were not confined exclusively to wrought
metal, but which occurred in castings, were observed in metal which
had fulfilled all the requirements of standard specifications, and the
authors were led to the conclusion that these specifications were
inadequate.
The service strength of brass and bronze is dependent, not on the
* Proceedings of the American Society for Testing Materials, 1917, vol. xxii. p. 213.
254 Abstracts of Papers
ultimate strength, but on the yield point. The true yield point should
therefore be specified, and a method should therefore be devised for
determining the yield point more accurately than can be done by the
current methods. A test in which the load is applied in increments
every five minutes is recommended.
If brass or bronze contains initial stress, the service strength is no
longer indicated by the yield point, but by the difference between the
initial stress and the yield point. Initial stress must therefore be
limited by specification, and suitable methods provided for its measure-
ment.
It is common practice to " burn-in " defects in brass castings.
When a " burn-in " cools, it may leave initial stress of such magnitude
that the casting will fail locally. Specifications for brass and bronze
castings should therefore provide for annealing of all castings which
have been repaired by " burning-in."
Molten copper is very susceptible to oxidation, and oxidized
brass or bronze is of very low strength and gives a low elongation. It
is recommended that a tensile test with a suitable elongation require-
ment be incorporated in every specification. — D. H.
Platinum Substitutes.- — The development of substitutes for plati-
num is discussed by F. A. Fahrenwald.* The production, market,
and uses are considered, the various fields in which satisfactory sub-
stitutes have been found being indicated. It is pointed out, however,
that while platinum has been successfully replaced in a number of
specific instances, research has not yet produced a substance which in
all its properties can serve as a general purpose substitute.
Specifications for a substitute are given, viz. (1) High melting
point. (2) Resistance to attack by mineral acids or alkalies, either
fused or in solution, and resistance to oxidation at all temperatm-es
up to its melting-point. (3) MalleabiUty and ductility and sufficient
strength to withstand stresses when in use. (4) Earity, high cost,
and platinum-white colour are the chief requirements for jewellery
purposes.
The possibilities of finding a satisfactory substitute are fully
discussed. The periodic table is introduced and consulted with a
view to eliminating all possible combinations which offer no promise
of success. The physico-chemical principles of alloys are appHed to
the problem and the conclusion adopted that the substitute for platinum
must be a homogeneous solid solution.
Of the metals adjacent to platinum in the periodic table, viz.
iridium, rhodium, palladium, silver, and gold, not one is suitable as
a general substitute for platinum. Iridium and rhodium are very
refractory, not readily workable, rare, and expensive. Palladium
meets most physical requirements, but is readily oxidized or carbonized,
* Journal of Industrial and Engineering Chemistry, June 1917, vol. ix. p. 590.
Properties of Metals and Alloys 255
and is quite soluble in common acids, e.g. nitric. Silver is too soluble
in acids, and has too low a melting point. Gold has the nearest resem-
blance, but is too soft, and is insufficiently refractory.
To alloy any of these metals it is necessary to ehminate or neutralize
any undesirable features and to develop desirable properties.
Alloys of gold and palladium are foimd to offer the greatest
possibilities.
Experimental work on those alloys is described. Small percentages
of rhodium are necessary for certain electrical and other purposes, and
of silver for some non-chemical applications. The affinity of palladium
for gases and impurities is to be guarded against, also inhomogeneity
due to segregation.
The chemical properties of " rhotanium " (the name appUed to
this series of alloys) are, with the exception of resistance to strong
nitric acid, equal to those of platinum.
Losses by volatilization of these alloys have been determined and
are tabulated with those of platinum. Pm'e palladium gains in weight.
The physical properties are described. All the alloys are practically
white, and are malleable and ductile. A table giving the melting
points, hardness numbers (scleroscope), tensile strengths, electrical
conductivities, and temperature coefi&cients is given. Owing to
greater strength and lower specific gravity, articles of rhotanium weigh
half, or less than half, as much as similar articles of platinum.
The high resistance and low temperature coeflS.cient give rhotanium
superiority over platinum as resistor elements in electric -heating units.
At temperatures below 1300° C. it is not oxidized and is less volatile
than platinum. It is satisfactory for contact terminals in many forms
of automatic electric devices. When used on a high-duty aeroplane
engine magneto it gave negative results. Khotanium has proved to
be equally as good as platinum for dental purposes.
For jewellery rhotanium is superior to platinum, being harder
and stronger, untarnishable and incorrodible.
Substitutes for platinum are discussed by E. Haynes.* Gold-
palladiimi alloy is a partial substitute for crucibles and dishes. Bulk
for bulk, it is about half the price of platinum.
An alloy of nickel and chromium, known as chromyl, may in
some cases be substituted for platinum for electric resistance coils
for combustion tubes and electric furnaces. Also, if used with pure
nickel or nickel-siHcon alloy, a serviceable thermocouple may be made.
Silicon-iron alloys and fused siHcon vessels are used for evaporations.
StelHte alloys are briefly described. The malleable alloys consist
of cobalt and chromium (the latter varying from 10 to 50 per cent.).
The alloys are all hard and difficult to machine. They have been
forged into table-ware, surgical instruments, evaporating dishes, and
jewellery. They are slowly attacked by dilute acids, but are immune
• Journal of IndtutrMand Erujineering Chemistry, October 1917, vol. ix. p. 974.
266 Abstracts of Papers
to all chemical combinations as well as fruit acids and acid vapours.
Vessels retain tlieir lustre well in the laboratory under nearly all
conditions.
They are strong at high temperatures, and are used for lamp-stands,
rings, triangles, &c.
StelHte would in many cases replace platinum in jewellery. Being
harder, it retains its lustre longer than platinum. It is also immune
against tarnish or corrosion in the air. — F. J.
Pyrophoric Alloys, Electrolytic Preparation o!. — E. Kremann,
R. Schadinger, and R. Kropsch * have made experiments on the
electrolysis of solutions containing salts of iron and cerium, to which
glycerol has been added in quantities ranging from 50 to 75 per cent,
of the solution. The deposits on the cathode contain cerium, although
in smaller proportions than in the technical pyrophoric alloys. Cerium
is sometimes deposited as the result of secondary reactions. The
pyrophoric properties are not more pronounced than in the alloys
of magnesium and iron, prepared by the same method. Photo-
micrographs of the deposits accompany the paper. — C. H. D.
Zinc Selenide. — Zinc and selenium, as observed by M. Chikashige
and R. Kurosawa, f do not mix in the liquid state. On prolonged
heating, however, combination takes place to a compound ZnSc,
which is quite insoluble in the melt. The three constituents are
therefore seen quite separately on coohng. The compound is brittle
and of bright yellow colour, of specific gravity 5-29, and is not changed
by heating to 1100° C— C. H. D.
lU.—INDUSTBIAL APPLICATIONS.
Aluminium, Industrial Uses. — F. G. Shull J refers to a number of
uses to which aluminium has been put during the last few years.
Aluminium foil has been used extensively as a wrapping for some
years, and its use has recently been extended by the development
of the process for embossing and printing of metal foil, and a consider-
able tonnage is now used in this form as a wrapping for chocolate,
toilet soap, &c. Plain foil has been used for making electrical con-
densers, and it is now being used as a lining for cartons for the packing
of coffee. Aluminium bottle caps and jar closures are also being
largely used. The development of the process for the welding of
aluminium by means of the oxy-acetylene flame has opened up a
* Monatshefte fur Chemie, 1917, vol. xxxviii. p. 91.
t Memoirs of the College of Science, Kyoto, 1917, vol. ii. p. 245.
j Traneactions of the American InatittUe of Metals, 1917, vol. xi. p. 88,
Properties of Metals and Alloys 257
very wide field for the outlet of aluminium. All sizes of sheet of gauges
heavier than about ^ of an inch can be welded, and the seams can be
dressed off, so that it is difficult to detect the weld. Die-castings of
aluminium are now produced regularly on a commercial scale, while
the production of aluminium tubing for pneumatic apparatus has been
extended.
One of the most interesting developments of recent years is the
production of aluminium alloy rods by rolling. Until recently alu-
minium alloy rods had been produced by drawing, and this method of
manufacture prevented the addition of any appreciable amount of
alloying element. Not only is the number of possible alloys increased
by the adoption of the method of rolling, but a more homogeneous
product is obtained. One of the first uses to which this rolled rod
was put was the production of fuse-timing parts for shrapnel, but
the amount of scrap produced was excessive, and the method was
discarded in favour of one in which the parts were produced by sand
casting by a compression process.
Aluminium cable, steel reinforced, is not a very recent product,
but its use has been extended by the increase in long-span, high voltage
systems. Aluminium has a coefficient of expansion about one-third
greater than copper, so that the lengthening of a long span in hot
weather is considerable. With low voltages and short spans this was
a matter of little importance, but -^-ith the adoption of long spans
this property became a serious menace to its existence. In order,
therefore, to compensate for the lack of strength and high expansion,
the cables were constructed of a core of stranded steel wires, on the
outside of which the aluminium conductor was wound. These cables
were a great success, and are very extensively used on the American
continent. — D. H.
Brass-Rolling Mill Alloys. — The non-ferrous alloys employed in
brass-rolling mills are described by R. A. Wood.* By far the greater
number <5f these alloys are simple zinc-copper alloys, to which, in
some cases, small quantities of another metal or metals are added.
The metals employed for making up the alloy must be of good
quality and practically free from impurities. Antimony and bismuth
must be avoided, even in traces, as they tend to produce cracking, either
in the rolls or during subsequent annealing, while, if the metal success-
fully passes through the manufacturing operations, season cracks will
most probably develop, sooner or later, in the finished product. Copper
and its alloys readily absorb sulphur, which causes the metal to become
spongy and porous in spots ; if present in quantity it produces brittle -
ness. Sulphur is absorbed from furnace gases during melting, and the
metal therefore should be protected as much as possible from these
gases. Much of the harmful efiect of sulphurous gases can be avoided
* Transactions •/ the American Inttitute of Metals, 1917, vol. xi. p. 181.
VOL. XIX S-
258 Abstracts of Papers
by the plentiful use of finely broken charcoal, which absorbs them
readily. The presence of arsenic, to any considerable extent, should
also be avoided.
An alloy of 50 parts of copper with 50 parts of zinc possesses the
highest zinc content the brass may contain, and still be " workable."
Both wire and sheet can be made from this alloy, but the operations
are very tedious. Alloys containing 57 to 63 per cent, copper are used
for making rods, tubes, and shapes of varying cross-section, by the
process of extrusion, the operation being carried out hot, but the work
is frequently finished off with one or two cold drafts on a draw-bench.
Mixtures of this composition are also rolled hot, and are indeed repre-
sentative of the commercially hot-worked alloys. Alloys containing
less than 60 per cent, copper cannot be worked cold successfully.
The annealing of zinc-copper alloys requires considerable care.
The alloys high in zinc are apt to " run " in places if overheated. They
are very soft and pliable at a red heat, but become hard on coohng ;
if, however, they are quenched direct from the anneaUng furnace, they
vnW remain much softer than if allowed to cool gradually. This
operation, however, is accompanied by some risk of cracking. Such
cracks are known as " water -cracks," and may be prevented by the
use of a fine spray. " Fire-cracks," which are developed during
annealing, are supposed to be due to unequal stresses in the metal.
A metal which has been thoroughly worked seldom " fire-cracks."
Alloys containing 80 per cent, or more of copper often contain small
pin-holes, bhsters, and spills. These defects are invariably to be traced
to the casting. High copper alloys are not quite so easy to cast as
high zinc mixtures, and some manufacturers have installed large
reverberatory furnaces, from which the molten copper is ladled into
crucibles containing weighed quantities of pre-heated zinc.
Where the alloys are required to be machined, a certain amount of
lead is frequently added. These mixtures should not be over-heated,
and they must be treated rather carefully during rolling, as they are
somewhat liable to crack. The amount of lead varies from 13 per cent.
Where a fine-grained alloy of high strength is required, a brass
base mixture with the addition of tin may be used. The metal should
not be over-heated, and the tin should be added and pushed under the
surface of the metal as quickly as possible, shortly before it is poured.
Tin seems to aid the production of season cracks.
Straight tin-copper alloys are known under the commercial name
of tin bronzes. [This term is not in accordance with accepted British
nomenclature. — Ed.] They are not difficult to roll while the per-
centage of tin is small, but between 5 and 10 per cent, tin they are
both difficult to roll and difficult to cast. A little phosphor-copper
or phosphor-tin, to deoxidize the melt, added just before casting,
simphfies the manufacture of good ingots.
Where very dense grain associated with great strength are re-
quired, iron may be added to the mixture. The addition of iron
Properties of Metals and Alloys; 259
increases the amount of piping, and renders casting difficult. It
also tends to segregate in the form of small hard nodules. It is best
added in the form of an alloy with 50 per cent, of copper, while a
little manganese, in the form of cupro-manganese, materially assists
the distribution of the iron. The alloys containing iron are very
springy, and will not take the same heavy reductions as zinc-copper
alloys. Lead may be added to these alloys to give free machining
properties, but it must not be overlooked that, especially in the
presence of tin, it renders the metal fragile at dull red heat.
Cupro-nickel, which varies from 5 to 25 per cent, of nickel, is made
by melting nickel and copper together. The temperature required
is very high. The character of the casting may be judged by the
surface of the metal as it is poured. If it appears agitated and
spits while the metal is being poured, it is an indication of a porous
casting.
Zinc-nickel-copper alloys are made in the same manner from a
zinc-copper base. Tin is seldom used, but iron, lead, and manganese,
the latter mainly as a deoxidizer, are frequently present. The ratio
of copper to zinc is generally about five to two, and the nickel may
vary up to 30 per cent. These alloys are used for cutlery. — D. H.
Bronzes for Bridge Construction. — 0. E. Selby * discusses the use
of bronzes in the construction of movable bridges and railway turn-
tables. He describes the conditions under which they are used, and dis-
cusses the requirements for different purposes. Four grades of bronze
are suggested, and specifications are given for each kind. Grade A, to
be used in contact with hardened steel discs under pressures exceeding
1500 lb. per square inch, should contain about 80 per cent, of copper
and 20 per cent, of tin, with a maximum of 1 per cent, of phosphorus.
It should have an elastic Hmit in compression of 25,000 to 40,000 lb.
per square inch. Grade B, to be used in contact with soft steel at
low speeds, under pressures not exceeding 1500 lb. per square inch,
such as trunnions and journals of bascule and lift bridges, should
contain about 85 per cent, of copper and 15 per cent, of tin, with a
maximum of 1 per cent, of phosphorus. It should have an elastic
Umit in compression of 19,000 to 23,000 lb. per square inch. Grade C
is for ordinary machinery bearings, and contains about 80 per cent,
of copper, 10 per cent, of tin, and 10 per cent, of lead, with 0-7 to
I'O per cent, of phosphorus, and its elastic limit in compression should
be 15,000 to 20,000 lb. per square inch. Grade D, for gears, worm
wheels, nuts, and similar parts which are subjected to other than
compressive stresses, is the ordinary Admiralty bronze, with a maximum
phosphorus content of 0 25 per cent. — D. H.
Die-Castings, Swelling o£ Zinc Alloy. — An investigation into the
.swelling of a zinc alloy, in the form of die-castings, is described by
* Transactions of the American Institute of Metals, 1917, vol. si. p. 359.
260 Abstracts of Papers
H. M Williams.* The alloy contained 5 5 per cent, of copper, 7 5 per
cent, of tin, TO per cent, of aluminium, and the remainder zinc, and
it was found that under certain conditions die-castings made from
this alloy swelled considerably. Most of the cases were found to
come from Cuba, and it was found that batches cast under the same
conditions swelled much more when stored in the Havana office of
the manufacturing company than when kept at the factory at Bridge-
port, Ct. It was then found that this swelling could be hastened
artificially, and different castings were stored at 98° and 176° F. in
moist air, at 212° F. in dry air, and in steam at 10 pounds and 45 pounds
pressure. It was found that storing in moist air at 176° F. produced
the most rapid swelUng, as much as 0 02 in. on a 2-in. diameter being
obtained. Casting temperature, casting pressure, annealing under
various conditions, and oxidation were all found to have no influence
on the phenomenon, and it was finally traced to the presence of
aluminium. Alloys were made in which the aluminium was varied
between 1 per cent, and Ol per cent., and these were gtored under
varying conditions. The alloy containing O'l per cent, of aluminium
showed little or no swelHng under any of the conditions, but it was
quite marked when 0 25 per cent, of this element was present, a>
much as 0 0139 in. expansion on 2 in. being observed after storinii
at 176° F. After a reduction in the aluminium content to O'l per
cent, had been made, no further trouble was experienced.
It is stated that if the original metal, containing 1 per cent, of
almninium, is cast imder ordinary conditions and cooled slowly, this
trouble is not experienced. — D. H.
Metallurgy in Italy. — An address on the progress and problems of
modern metallurgy has been pubhshed by D. Meneghini.t Attention
is called to the necessity of developing electro-metallurgical methods in
Italy, in view of the almost complete absence of coal, and of the presence
of much unused water-power in the Alpine regions.
The conditions are more fully discussed by A. Miolati.J Artificial
graphite and silicon are now being manufactured by electrical processes
in works using water-power, whilst steel and ferro-alloys are made on a
large scale in electric furnaces. Experiments on the electric smelting
of zinc ores have been made, but it does not appear that the results
have been promising ; the construction of a low-temperature electric
furnace, capable of working regularly and uniformly at temperatures
not much over 1000° C, is very desirable. The production of zinc
by the electrolysis of the fused chloride also deserves further study
Sodium has been prepared in small quantity, whilst aluminium is
already produced on a considerable scale from native bauxite.
Electrolytic refining of copper and detinning of tinplate are carried
out on a small scale. — C. H. D.
* Proceedings of the American Institute of Metals, 1917.
t Annali di Chimica Applicata, 1916, vol. V. p. 161.
t Ibid., p. 251.
Properties of Metals and Alloys 261
Metal-Spraying Process. — The principles and applications of the
Schoop metal-spraying process are discussed at some length by Hans
^Vrnold.* The paper is very critical, and the author's work leads him
to the opinion that many of the impressions derived from a study of
the publications of the Schoop Companies which have been formed all
over the world are erroneous.
The author shows that the metal particles are drawn away from
the rod of metal in much the same way as drops from a glass rod.
They have an oval shape, and vary considerably in size — 0 01 to
015 mm. in the same metal sprayed from the same apparatus.
The structiu'e of the particles is crystalline, although Schoop asserts
that it is amorphous. Not only are the crystals visible under the
microscope, but lines of slip, caused by the deformation of the particles,
can be detected. The most characteristic property of the sprayed
particles, however, is their undulating contours, which are the result
of the flattening of the particles at the moment of impact. The hnes
of demarcation between the individual particles are quite distinct, and
Schoop 's assertion that they become welded together at the moment
of impact is disproved, except in the case of some metals of low melting
point. All that the microscopic examination reveals is that they
are in a soft condition when they reach the substratum, or they are re-
softened by the impact. The author shows from theoretical reasoning
that the velocities necessary to obtain fusion of the particles are much
greater than can be obtained from gas projected from a simple nozzle,
Avhile actual practical measurements demonstrate that the velocities
are in fact very low, and that Schoop 's assumption that they are at
least equal to that of a German rifle bullet is inadmissible. The actual
value obtained in the case of brass was 120 metres per second, while
the calculated velocity necessary to melt the paiiicle was of the order
of ten times this amount.
There is no tendency for the sprayed paiticles to alloy with the
substratum on to which they are sprayed, unless submitted to special
after-treatment. Whereas in the case of hot galvanizing a stratum
of alloy is seen at the junction of zinc and iron, there is a definite gap
between these two metals in the case of a sprayed coating. It is
therefore necessary to roughen the surface of articles to be coated, and
for this a sand blast is recommended, it being considered that piclding
with acid does not give sufl&cient roughness. This roughness is essential
in order that the particles shall penetrate into the depressions, and
adherent coatings can only be obtained if this condition is fulfilled.
In any case, since no alloy is formed, the adhesion is considerably
less than in the case of galvanizing or tinning ; and a further defect
of the process is to be found in the coarseness of the particles, which
leads to the Separation of the coating if the article is subjected to
bending. Tliis has given considerable trouble in practice. Trouble
♦ The MeUd Industry, 1918, vol. xii. (7), p. 121.
262 Abstracts of Papers
is also experienced on account of the difierent expansions of the
article and its coating. Metallic bodies or coatings produced by spray-
ing are not at all comparable with castings, but are rather a kind of
metal millboard, the individual particles of which are felted or matted
together.
The density of sprayed coatings of a number of metals was deter-
mined. In all cases the sprayed metal had a density considerably
less than that of the cast metal, and in the case of copper the value was
16 per cent, lower than that of the cast material. Moreover, the values
for difierent samples of the same coating vary considerably, and show
that the structure varies even imder identical methods of production.
The assumption that sprayed coatings contain a certain amount of
oxide has been verified by experiment. Sprayed copper, for example,
on pohshing and etching, showed large numbers of particles of cuprous
oxide, which coalesced on anneaUng, and chemical analysis of the
sample showed that it contained as much as 0"4 per cent, of oxygen,
corresponding to 4 per cent, of oxide. Despite all previous denials,
the presence of oxide is probable ah initio, and Schoop recommends
the substitution of an inert gas instead of air. The author, however,
considers that the compressed air has been unjustly blamed, and that
the oxidation occurs in the oxy-hydrogen flame itself, which is
sufficiently hot to entail the dissociation of part of the water vapour
formed, with the production of nascent ox}-gen. It is noteworthy
that both zinc ancl brass are nearly free from oxide after spraying,
and it is thought that the zinc has a reducing action, the resulting Ught
zinc oxide being driven ofi. Iron undergoes very Uttle oxidation,
while silver steel, which was pearhtic before spraying, exhibited a
martensitic structure after the operation.
The hardness of sprayed material, tested with a Martens-Heyu
ball tester, was generally inferior to that of the cast metal, but this
is attributed to the porous natm-e of the mass. It is probable that
the actual sprayed particles are harder than the cast metal.
It would appear that for purposes in which density and mechanical
sohdity of the material are important, this process is not likely
to prove satisfactory. On the other hand, there are many operations,
such, for example, as the coating of cast iron vdth. zinc or tin, an operation
usually attended with difficulty, in which the process may find applica-
tion, while for articles of complicated shape which must not be altered
by heating, this operation can be easily applied. In any case, the
coating of non-metallic ai-ticles, such as wood, is a matter of great
importance. In the chemical industry, the porous character of the
coatings is usually a fatal objection, and in this connection it may be
stated that iron coated \s'ith aluminium begins to rust in a very short
time. »
The author then enters into the question of cost, and comes to
the conclusion that this process must always compare unfavourably
with that of hot-galvanizing, chiefly on account of the use of expensive
Properbies of Metals and Alloys 263
wire, the high cost of the gases, and the necessity for skilled labour.
In the author's view, much remains to be done before the process can
become a commercial success, and in this connection the invention
of Genecke * is of great importance. He has constructed an apparatus
in which coal-gas, drawn directly from the main, can be used as the
heating gas, and the combustion of the coal-gas can be effected by
the compressed air itself. This is, in the author's opinion, the most
promising improvement that has been made in the spraying pistol.
— D. H.
Nickel in Canada. — A short account of recent developments in
the Canadian nickel industry is given by E. P. Mathewson.f The
greatest demand for nickel is for the manufacture of nickel steel for
structural purposes. Very large electrolytic plant is in course of
erection, but will not be ready for use until next year. The supply
of ore has been found to be much larger than was formerly supposed.
— C. H. D.
Specifications £or Brass Condenser Tubes. — An investigation has
been undertaken by A. E. White \ with the object of accounting for
the sphtting of certain brass condenser tubes in service, and to deter-
mine the proper chemical composition and mechanical and thermal
treatment winch should be given during manufacture. The author
also formulates specifications likely to be of material assistance in
the purchase of tubes.
Splitting is almost invariably due to faulty manufacture, and not
to the chemical composition. Excessive pinching during drawing,
insufficient anneahng between the drawings, and an omission of
anneaUng or incomplete anneahng after the final drawing, are among
the conditions responsible for sphtting.
The author discusses the chemical compositions of a number of
condenser tube alloys, and concludes that a composition of 70 per cent,
of copper and 30 per cent, of zinc is most suitable, for the following
reasons : it has the maximum amount of ductihty ; it has an adequate
tensile strength ; it is more readily annealed and drawn than alloys
of higher zinc content ; it contains only one micrographic constituent,
and is therefore less liable to failure by electrolytic action. Lead
should not be present in greater amount than 01 per cent. ; arsenic
and antimony should be kept under 0 02 and 0 002 per cent, respectively,
and iron is not harmfvd provided that it does not exceed 0 075 per
cent.
The author is of the opinion that the best tubes are produced by
giving the material as much cold work as it will stand, provided always
that it is not " over-drawn " between the anneahngs, and he further
* German Patent 299490 ; Zeilschrift fiir angewandte Chemie, 1917, 30 (11.), p. 281.
t Journal of the Society of Chemical Industry, 1918, vol. xxxvii. p. 53.
j Proceedings of the American Society for Testing Materials, 1916, vol. xvi. p. 153.
264 Abstracts of Papers
considers that a large number of light drafts are preferable to a smaller
number of heavy drafts.
Annealing between each set of cold-drawings should be carried
out at such a temperature that the grain distortion caused by the
mechanical treatment is completely removed, but not so high that
coarse crystals are produced. For the final annealing the tubes should
be annealed just sufficiently to break down the distorted structuie
produced by the last drafts.
A long discussion followed the reading of this paper, in which a
number of the author's conclusions, especially with regard to the
mechanical and thermal treatment of the tubes, were questioned. — D. II.
Titanium, Alloys of. — The manufacture of titanium alloys is de-
scribed by A. J. Rossi.* Ferro-titanium containing up to 85 per
cent, of titanium is readily prepared in the electric furnace, but such
alloys are too hard for use, scratching glass or even quartz. In order to
avoid the presence of carbon, aluminium is melted at the Niagara
Falls works, and rutile and scrap iron are charged directly into the
bath. For copper-titanium, rutile and aluminium are charged into
a bath of copper, the best product containing from 10 to 15 per cent,
of titanium, this alloy being very suitable for deoxidizing brasses,
bronzes, and aluminium bronzes. Aluminium-titanium alloys con-
taining 45 per cent, of titanium have also been used for the latter
purpose. — C. H. D.
lY. —COBBOSION.
Condenser Tubing, Corrosion of. — A case of corrosion of brass
condenser tubes, fitted in a stationary condenser of marine type -and
used for cooUng warm fresh water, is described by J. Kewley.f The
cooling water, on the inside, was brackish dock water containing large
quantities of magnesium sulphate and chloride. The corrosion, which
caused leakage after four months, was confined to a length of 2 in.
from the end of each tube at which the brackish water entered. It
was greatest in the lowest part, at which the difference of temperature
between the entering and issuing water was least. The brass contained
copper 70-68, zinc 2881, tin 017, lead 018, and iron 020 per cent.
An exactly similar condenser, working under the same conditions,
but with tubes of a copper-zinc alloy containing 2 per cent, lead, showed
no corrosion after two years.
The tubes were lengthened by means of a sleeve, and allowed to
project 9 in. from the cast iron plate. When corrosion had taken
place, the tube was pushed along so that the corroded inlet ends
♦ Journal of the Society of Chemical Industry, 1918 ,vol. xxxvii. p. 73.
t Ibid., 1918, vol. xxxvii. p. 39.
Properties of Metals and Alloys 265
projected and could be cut off, so saving the expense of re-tubing the
condenser. — C. H. D.
Lead Roofing, Corrosion of. — Two cases of corrosion of sheet lead
used for roofing are described by J. S. S. Branie.* In the first case
the cast sheets had been in use for a long period (probably 200 years),
and were attached to wood. AVhere the lead was in actual contact
with the oak beams, perforation had taken place. The crust of white
deposit at these points proved to consist of basic carbonate, identical
with commercial white lead. The action has been attributed in previous
instances to the action of acetic acid from the oak wood, but has not
been more fully investigated.
The second case was that of lead laid on coke-breeze concrete,
where the patches of material between lead and concrete proved to
be litharge, coloured red by the presence of a small quantity of a
higher oxide. The action is attributed to the influence of the calcium
hydroxide in the concrete. Not more than a trace of sulphur was
found in the corrosion product.
In the course of the discussion, it was pointed out that the bad
influence of Portland cement on lead was well known, and that the
initial formation of a calcium plumbite was probably the cause.
•Another case of the formation of basic lead carbonate is described
by F. Southerden.f Lead roofing sheets in Axminster Chiu'ch, laid
on oak boards so recently as 1909, were converted on the under side
into a yellowish-white mass having the composition 2PbC'03, Pb(0H)2,
and perforation had taken place at several points. Lead sheets in the
same roof, laid on deal in 1833, were quite sound. A solution of tannin
dissolves clean lead. — C. H. D.
Muntz Metal, Selective Corrosion of. — Some typical cases of selective
corrosion of Muntz metal are described by H. S. Kawdon.t A bolt
taken from the keel of a lifeboat after six years' service was converted
to a cei-tain depth into a mass of porous copper, the action penetrating
farthest at that point at which the bolt was subjected to the most
severe alternating stresses in use. Sheathing which had been in use
for seven years on an anchored hghtship was so brittle that it could
be broken into rectangular pieces with the fingers. In both these
cases the y8 constituent had been converted into copper, the a being
almost unchanged. Some condenser tubes had been so far acted on
from the salt-water side that both constituents had been deprived of
zinc, but an intermediate zone was found between the copper and
unchanged brass, within which only the fi was attacked. A bolt
fractured at the angle between bolt and head, the corrosion being
greatest at that point.
* Journal of the Hocidy of Chemical Indualnj, 1918, vol. sxxvii. p. 39.
t Ihid., vol. xxxvii. p. 85. —^
X Techndogk Papers of the Bureau of Stavdards, 1917, No. 103, p. 1.
266 Abstracts of Papers
Laminations, parallel with the surface, were sometimes observed,
representing intermittent periods of service. In a-brass the cor-
rosion advances along the boundaries of the crystal grains. In /3
crystals the corrosion advances along certain planes, of which there are
sometimes two intersecting sets in the same grain. An outer layer of
a-brass, such as is produced by loss of zinc during the manufacture
of Muntz metal condenser tubes, serves as a protection to the under-
lying duplex alloy. Contact with a more electro-negative metal,
such as copper, accelerates corrosion locally, but this could not be
considered as an important factor in any of the cases examined. Basic
zinc chloride, formed as a product of corrosion, has also an accelerating
influence. Annealing, either above or below the transformation point
at 470° C, has little influence.
Specimens with a transverse groove were kept under tensile stress
in a solution of sodium chloride. When the elastic limit of the alloy
was exceeded, selective corrosion was found to take place in most
cases at the groove, any basic salt formed being removed from time
to time to avoid complications. — C, H. D.
( 267 )
METHODS OF ANALYSIS ; PHYSICAL AND
MECHANICAL TESTING; AND PYROMETRY.
CONTENTS.
PAGE
I. MethoSs of Analysis ......... 267
n. Physical and Mechanical Testing 276
m. PjTonietry 280
I.— METHODS OF ANALYSIS.
Aluminium Alloys. — Full details of methods which have been
successfiil in the analysis of hght aluminium alloys are given by B.
ColHtt and W. Kegan.* For alloys containing from 10 to 15 per cent,
of copper, with or without manganese, it is recommended to heat a
gramme with sodium hydroxide solution, or with water and sodium
peroxide. After diluting to 250 c.c. and boiling, the metalhc copper
and manganese are filtered off, washed, and dissolved in nitric acid.
Copper is then estimated by the thiosulphate method, preferably with
the addition of fluoride to ehminate any error due to the presence of
iron. For manganese, a gramme of the alloy is attacked by sodium
hydroxide as before, cooled, neutralized with nitric acid, and 35 c.c.
of concentrated nitric acid added in excess. The manganese is then
oxidized by the bismuthate method or by means of persulphate, and
titrated with sodium arsenite.
It must be noted that these alloys are liable to vary in composition
in different parts of the same casting.
When the alloy contains 5 per cent, of copper or less, together
with zinc (up to 20 per cent.) and other metals, copper may be
estimated by attacking 2 grms. with sodium hydroxide, acidifying
with hydrochloric and nitric acids, and precipitating copper by means
of hydrogen sulphide, using the filtrate for estimations of iron and
magnesium. The precipitate is dissolved in nitric acid and estimated
iodometrically.
Alternatively, 2 grms. are taken for a silicon estimation, 30 c.c.
of concentrated hydrochloric acid and 10 c.c. of concentrated nitric
acid being used for solution. The action is very violent. After
evaporating with 30 c.c. of concentrated sulphuric acid until fumes are
* Journal of the Society of Chemical Industry, 1918, vol. xxxvii. p. 91.
268 Abstracts of Papers
evolved, the mass is dissolved in water, and the mixture of silica and
silicon collected. The copper is precipitated from the filtrate by
boiling with sodium thiosulphate, and the precipitated sulphide roasted
to oxide in a mufile. Iron is titrated with permanganate after
leduction by staimous chloride, and magnesium by the usual method.
For nickel, it is not necessary to remove copper before precipitating
with dimethylglyoxime .
For the analysis of the rich alloys or " hardeners" used in making
up alloys of this class, a typical exam])le of which contained 30 per
cent, of copper, 1"6 per cent, of iron, and 166 per cent, of nickel, rather
different methods are necessary : 2 or 3 grms. are dissolved in hydro-
chloric and nitric acids, evaporated with sulphuric acfd, and silica
collected. Copper is precipitated from the filtrate by means of hydro-
gen sulphide, and iron and aluminium then precipitated together
as hydroxides. Aluminiimi is redissolved by boihng with sodium
hydroxide. For the nickel estimation, attack by sodium hydi'oxide
followed by acidification may be used. — 0. H. D.
Antimonial Lead, the Analysis of. — The method of Dcmorest for
the analysis of antimonial lead is regarded as a suitable one if modified
as described by C. R. McCabe.*
The chief difiiculty in the process is the absorption of antimonious
sulphate by the precipitated lead sulphate. In the modified procedure,
the purification of the lead sulphate is efiected.
The successive steps in the procedure are as follows :
(1) Dissolving the alloy in concentrated sulphuric acid.
(2) Diluting to precipitate lead sulphate in a purer condition.
(3) Boihng to further pmify precipitate, tin goes wholly into solution
and the greater part of the antimony.
(4) Filtration.
(5) Dissohang of lead sulphate precipitate in ammonium acetate
and reprecipitating -svith sulphuric acid. Antimony is now wholly
in solution.
(6) Filtering. Lead is determined as sulphate, antimony being
iletcrmined in the two filtrates by titration with potassium perman-
ganate and ferrous sulphate. Tin is determined in the first filtrate by
the iron reduction and iodine titration method.
The procedure is fully described and accompanied by full pre-
cautionary notes. — F. J.
Brass or Bronze and Babbitt Analysis. — E. W. Hagmaier f gives
two schemes of analysis, one for brass or bronze, and the other for
babbitt metal. The methods of analysis which he gives are by no
means new, and the principal object of the author is to develop a
method in which the manipulation is so arranged that there is as little
♦ Journal of Indmtrialand Ermineering Chemistry, Jan. 1917, vol. ix. p. 42.
t Journal of the American Institute of Metals, 1917, vol. xi. p. 370.
Methods of Analysis, Testing and Pyrometry 269
loss of time as possible. The author gives, firstly, an account of the
method used for each particular element ; and, secondly, the scheme
for the simultaneous manipulation of these methods. — D. H.
Cadmium, Detection of. — A note by R. Salvador! * recommends
the following method for the detection of cadmium in presence of
other metals. The solution of the second group sulphides in nitric
acid is made ammoniacal, and the precipitate of bismuth hydroxide
is filtered off. An ammoniacal solution of ammonium perchlorate is
added to the filtrate, and cadmium is thrown down in the form of
white crystals of the salt, Cd(C104)2, 4NH3, which redissolve on heating
and crystallize on cooling, like lead chloride. A 17 per cent, solution
of ammonium perchlorate is most convenient, and one part of cadmiunr
in 3000 may be detected. The precipitate forms more slowly in
presence of an excess of copper, and in such cases time should be
allowed for the crystals to fall to the bottom of the test-
tube.— C. H. D.
Copper, lodometry of. — For estimating copper in presence of iron,
H. Ley f recommends the precipitation of the iron as ferric phosphate,
by adding sodium phosphate solution, followed by acetic acid. The
precipitate does not react with potassium iodide. It is proposed to
estimate the iron by titrating another portion of the original solution
vnih thiosulphate after adding potassium iodide ; the difference between
the two volumes of thiosulphate used gives the iron. (This method
of estimating iron is not to be recommended.) Aluminium and zinc
do not interfere with the reaction. — C. H. D.
Cupferron as a Reagent. — Further uses of cupferron (ammonium
phenylnitrosohydroxylamine) are described by J. Brown. | This
reagent quantitatively precipitates iron, titanium, and zirconium from
solutions which contain those elements together with aluminium and
manganese. The original solutions are made shghtly ammoniacal,
then an excess of sulphuric acid added, after which the liquid is cooled
in ice water and precipitated by adding a 6 per cent, solution of cup-
ferron, with constant stirring, a large excess being used. The precipi-
tate is quickly collected on a filter paper, and repeatedly washed with
10 per cent, hydrochloric acid. The filtrate and washings are kept for
the estimation of aluminium and manganese. The precipitate is
finally washed with ammonia, and ignited in a platinum crucible over
a Meker burner.
The iron in the precipitate is estimated after fusion with potassium
hydrogen sulphate. Methods are described for the separation of
titanium from zirconium. — C. H. D.
* Annali di Chimica Applicata, 1916, vol. v. p. 25.
t Chemiker-Zeitung, 1917, vol. xli. p. 763.
X Journal of the American Chemical Society, 1917, vol. 39, p. 2358.
270 Abstracts of Papers
Lead, Separation of Iron from. — For the separation of small quanti-
ties of iron from lead, J. F. Sacher * recommends heating 2 grms. of
the lead salt with an excess of nitric acid, evaporating to dryness,
and heating the residue to 100° 0. for fifteen minutes. The iron is thus
converted into the basic nitrate, and after collecting and washing with
hot water may be dissolved in hydrochloric acid, precipitated with
ammonia, and determined gravimetrically. Should lead sulphate
be present, it is dissolved in ammonium acetate solution from the
residue, before dissolving the iron. In presence of decomposable
silicates, the heating of the nitrates must be carried to 125°, this
temperature being without action on lead nitrate. — C. H. D.
Manganese, Colorimetric Estimation of. — The use of periodates
for the oxidation of manganese in this process is described by H. H.
Willard and L. H. Greathouse.f The reaction has the form :
2Mn{N0,)is + 5KI0, + 3HjO - 2HMn04 ^ SKIOj + 4HN0,.
Only a small excess of periodate is required, and the colour obtained
is the true permanganate colour.
The material to be tested is made into a solution containing at
least 10 to 15 c.c. of sulphuric, 20 c.c. of nitric, or 5 to 10 c.c. of syrupy
phosphoric acid, or a mixture of these, in 100 c.c. If carbon compounds
are present, as in steel, a little persulphate should be added to oxidize
them. Chlorides should have been removed. After adding 0 2 to 0-4
grm. of sodium or potassium periodate, the solution is boiled for a
minute, kept hot for five or ten minutes, cooled, diluted to a known
volume, and compared with a solution of known manganese content,
similarly treated.
Should much iron be present, the solution must contain either
sulphuric or phosphoric acid, as ferric periodate is insoluble in nitric
acid.— C. H. D.
"Nichrome," Notes on the Analysis of Cast. — Cast " nichrome "
containing 58 to 62 per cent, nickel, 23 to 26 per cent, iron, 8 to 14
per cent, chromium, 0'5 to 2 0 per cent, manganese, zinc and silica
0 2 to I'O per cent, carbon and sometimes a mere trace of copper which
is coming into general use presents certain difficulties of analysis,
which are discussed by E. W. Eeid.J
The difficulty of getting the alloy into solution is overcome by
first dissolving, removing the silica by HF. from the residue, then
dissolving the resulting residue in acid, subsequently fusing any un-
dissolved chromium with sodium peroxide. All filtrates are combined
to form a " stock " solution.
Nickel is determined by the potassium cyanide method, iron after
* Chemiker-Zeitiin/j, 1917, vol. xli. p. 245.
t Journal of the American Chemical Society, 1917, vol. xxxix. p. 2366.
j Journal of Industrial and Engineering Chemistry, May 1917, vol. ix. p. 488.
Methods of Analysis, Testing and Pyrometry 271
separation from chromium by titration with potassium permanganates,
reduction being efEected by zinc. Chromium is determined by the
addition of manganous sulphate, reduction by ferrous ammonium
sulphate, titrating the excess -with potassium permanganate.
Manganese is determined on a separate portion of the " stock "
solution, precipitating manganese with potassium chlorate. Ferrous
ammonium sulphate is used to dissolve the filtered precipitate, the
excess being titrated with potassium permanganate.
Zinc is determined in the filtrate from the iron-chromium precipita-
tion by the potassium ferro-cyanide method.
Carbon, if present, may be determined by direct combustion. — F. J.
Phosphor-Tin, a Volumetric Method for the Analysis of. — The need
of a method formulated specifically for the analysis of the alloy, phosphor-
tin, is shown by K. E. Lee, A. H. Fegeley, and F. H. Eeichel,* and
attention is called to the fact that the literature apparently does not
contain such a method.
A volumetric method has been developed by the authors, and is
described. The tests to which this method has been subjected indicate
that it is not only easy of execution, but is also rapid and accurate.
The method pro\ades for the determination by means of a train
of flasks. The alloy is dissolved in hydrochloric acid in the first flask
from which all air is excluded by means of a current of illuminating
gas or carbon dioxide. The tin dissolves as stannous chloride, and the
phosphorus is liberated as phosphine, which is absorbed by solutions
in the train of three flasks. The tin is determined at once, adding'
an excess of ferric chloride and determining the amount of ferric
iron reduced by the stannous chloride, by titrating with potassium
dichromate, using potassium ferricyanide as external indicator.
The phosphine is converted into phosphoric acid by the absorbing
solutions (potassium permanganate 2 grms. per litre with 10 per cent,
nitric acid added). From the absorbing solutions the acid is precipi-
tated as ammonium phosphomolybdate, which is reduced in a reductor
and finally titrated.
The two determinations may be completed in forty-five minutes,
whilst other methods require hom's.
The method provides for the detection of impurities in the alloy,
and is therefore as well adapted for careful assay work as for " con-
trol " analyses.
Potassium permanganate solutions are satisfactory absorbents
for phosphine, the oxidizing and absorbing power being markedly
increased by the addition of nitric acid. — F. J.
Phosphor-Zinc, Analysis of. — The following method is proposed by
G. Liberi f for the estimation of phosphorus in phosphor-zinc. From
* Journal of Industriai and Engineering Chemistry, July 1917, vol. ix. p. 663.
■f Annali di Chimica Applicata, 1917, vol. vii. p. 144.
272 Abstracts of Papers
0"2 to 0'3 grm. of the material is introduced into a generating flask
connected witli absorption bulbs containing a 3 per cent, solution of
silver nitrate, the air having been expelled from the apparatus by
means of carbon dioxide. Fifty c.c. of sulphuric acid (1 : 2) are then
added through a tap-funnel. Most of the hydrogen phosphide is
evolved in the cold, and the reaction is then completed by warming.
A slow stream of carbon dioxide is continued for a further half-hour.
Both the liquid and the precipitate in the bulbs are then washed out
nto a beaker, washed with dilute nitric acid, and warmed until the
precipitated silver has dissolved. The silver is then precipitated with
an excess of hydrochloric acid, and the phosphorus in the filtrate
estimated as magnesium pyrophosphate. — C. H. D.
Platinum Electrodes, Substitutes for. — On account of the great
expense of the usual platinum electrodes for analytical work, it has
been proposed by J. Gewecke * to use silvered glass basins, the electrical
contact with which is made by a strip of platinum foil bent over the
edge. Such basins have been used with success in the estimation of
copper, zinc, cadmium, cobalt, and nickel. The coating is cleaned
off with nitric acid after an estimation, and the glass is resilvered. —
C. H. D.
Platinum, Microchemical Detection of. — When small quantities of
platimim have to be detected^ in presence of a large excess of gold or
silver, as in assaying bullion, M. Van Breukeleveen f recommends
melting gold vnih. twice its weight of pure silver, the bead so obtained,
weighing about 0*75 grm., being then rolled out into a thin sheet. This
is heated with 25 c.c. of concentrated sulphuric acid for twenty minutes.
and after decanting and washing the residue is dissolved in a small
quantity of aqua regia, the solution evaporated to dryness, and again
evaporated with hydrochloric acid. The gold is converted into in-
soluble aurous chloride by heating to 170° to 190° C. for twenty minutes,
after which Ol c.c. of iV^/3 hydrochloric acid is added, and a drop,
after stirring, is taken for microscopical examination and mixed with a
little sohd potassium chloride. Platinum is recognized by the char-
acteristic octahedra. If formed, two more drops of acid are added to
the residue, and a drop taken for examination as before. This is
repeated until crystals no longer appear, and comparison tests are made
with gold containing a known proportion of platinum. For silver
the same method is followed, the silver being first melted with a small
proportion of gold. — C. H. D.
Recording Differential Dilatometer. — ^The development of a record-
ing difierential dilatometer, not only as an instrument of research,
but also as an apparatus of control in industrial practice, is described
* Chemiker-Zeitung, 1917, vol. xli. p. 297.
■\ Receuil des travaux chimiques dis Pays-Bas, 1917, vol. xxxvi. p. 285.
Methods of Analysis, Testing and Pyrometry 273
by P. Chevenard.* The method of thermal analysis, based on the
study of dilatation, has some advantages over the ordinary methods,
and it is claimed that it is one of the most sensitive and most convenient
methods for studying the phenomena of transformation. The indica-
tions of this method are practically independent of rates of variation
of temperature, and therefore readily permit of the study of the effects
of rate of temperature change between very wide limits. The method
also lends itself to the study of the efiects of annealing, quenching,
and cold-working.
The instrument compares the dilatation of the metal studied with
that of a suitably chosen standard. It traces a curve, of which the
ordinate is the difference between the dilatations of the two samples.
The temperature, on the other hand, is given by the actual dilatation
of the standard. Two tubes of fused silica, closed at one end, are
fixed firmly in a socket, which is fastened to the head of the instrument.
These tubes contain the specimens, which are in the form of cylindrical
rods, terminated at one end by a plane face, and at the other by a
sharp point, which rests against the hemispherical ends of the silica
tubes. Two small silica rods make contact with the plane faces of
the specimens, and transmit their dilatations to two hardened steel
cyUnders, which, in turn, move a small mirror, which amphfies these
dilatations. The optical lever which carries this mirror is pivoted
on three points, placed at the corners of a right-angled triangle, the
pivot at the right angle being in contact with the rod which transmits
the movement of the standard, while one of the other pivots is in
similar contact with the other specimen. The thii'd pivot is fixed.
The complex movement of this lever, produced by the dilatation of
the specimens, is equivalent to a rotation round one axis proportional
to the dilatation of the standard rod, and a rotation round the other
axis proportional to the difference of the dilatations of the two speci-
mens. The curve so traced is recorded on a photographic plate.
The two tubes of fused silica are heated in an electric furnace,
wound non-inductively in such a manner that the temperature shall
be as uniform as possible over that portion which contains the samples,
and further to secure this end the tubes are contained in an outer
metalUc muffle.
It is necessary to compensate for variations in temperature in the
amplifying mechanism. Whenever possible invar is used, while to
compensate for variations of the steel rods and pivots, these are mounted
on columns of 44 per cent, nickel steel, whose dilatation exactly com-
pensates that of the quenched steel.
The standard used was an alloy of nickel and chromium (10 per
cent, chromium), knoAvn under the name of '" Baros." It has a dilata-
tion which is almost exactly reversible, and which can be expressed
as a simple function of the temperature. The relationship is almost
* Eevue de Mita{lurgk, 1917, vol. 5, p. 610.
VOL. XIX. T
274 Abstracts of Papers
exactly linear, and the constants in the equation have been worked
out very carefully by independent experimenters. This alloy does
not undergo any appreciable change after repeated heatings, and is
little affected by oxidation.
The author has used the instrument in connection with investiga-
tions on the special steels and iron-nickel alloys, and is of the opinion
that the instrument is suitable for use as an appliance of industrial
control. — D. H.
Separation of Zinc from Cadmium and lodometric Determination
of Cadmium. — ^In the analysis of spelter, according to E. J. Ericson,*
much of the zinc is separated from cadmium (after removal of lead)
by crystalhzation as zinc sulphate. Cadmix;m is precipitated from
the remaining Uquor by hydrogen sulphide.
The precipitated cadmium sulphide may be treated by any of
the methods given in earlier papers, or treated iodometrically by von
Berg's method, in which an excess of iodine solution (iV/10) and dilute
hydrochloric acid are added, titration being effected with sodium
hyposulphite, using starch solution as indicator.
The method, as apphed to the determination of cadmium in zinc
ores, is described in detail. — F. J.
Sulphide Precipitates, Separation of. — A new method for the separa-
tion of the arsenic group of sulphides from the copper group is proposed
by M. C. Sneed,| with special reference to qualitative analysis. The
usual second group precipitate is collected and washed with hydrogen
sulphide water containing 2 per cent, of ammonium nitrate. It is
then digested with a reagent prepared as follows. A 12 per cent, solu-
tion of sodium hydroxide is saturated with hydrogen sulphide, and
each litre of this solution is mixed with 400 c.c. of a 40 per cent,
solution of sodium hydroxide. This separates the arsenic and copper
groups perfectly, mercury passing into solution with the ar-senic and
tin. The method is particularly suitable for the detection of small
quantities of arsenic. — C. H. D.
Tin and Tungsten, Separation of. — For this separation, Travers J
recommends the fusion of the finely ground material with anhydrous
sodium sulphite, using a porcelain crucible in a muflSe. Even -with 50
per cent, of tin, the ore is completely decomposed. After boiling out
with water, the solution is diluted to 700 c.c. and shghtly acidified.
Tin is then precipitated as sulphide, and is found to be quite free from
tungsten. It is purified by redissolving in ammonium polysulphide,
reprecipitating and igniting to oxide.
Tungsten is estimated in a separate sample, fused in the same way.
The fused mass is directly attacked by a mixture of concentrated
* Journal of Industrial and Engineering Chemistry, July 1917, p. 671.
t Journal of the American Chemical Society, 1918, vol. xl. p. 187.
1 Comptes rendus, 1917, vol. clxv. p. 408.
Methods of Analysis, Testing and Pyrometry 275
hydrochloric and nitric acids. Evaporation to dryness does not
render the whole of the tungsten insoluble ; the acid liquid is therefore
filtered, and ammonia is added, avoiding any excess. The iron thus
precipitated carries down tungsten and a little tin. It is washed,
dissolved in hydrochloric acid, evaporated to dryness, and extracted
with hydrochloric acid. The residiie is tungstic acid, with silica, which
may be estimated in the usual way.- — C. H. D.
Tungsten Powder, Valuation o£. — A simple method of determining
the quantity of metallic tungsten in commercial tungsten powder is
proposed by F. Hodes.* The powder is ignited in an open crucible,
the gain in weight representing the oxygen taken up by the metal.
As the material also contains small quantities of carbon and moisture,
it is necessary to take another small portion and to heat it in a tiibe
in a stream of oxygen, weighing the carbon dioxide and water evolved.
— 0. H. D.
White Metals, Method for Analysis. — For the estimation of lead,
copper, and antimony, E. Howden j recommends dissolving 1 gim.
of the alloy in a mixture of nitric and hydrochloric acids, adding 5 c.c.
of sulphuric acid and a gramme of tartaric acid, and heating until
fumes are no longer evolved. After diluting, the lead is collected as
sulphate. The filtrate is reduced by means of sulphur dioxide, and
the copper precipitated as iodide or as thiocyanate. This precipitate
is then dissolved in dilute nitric arid, and the copper estimated iodo-
metrically.
For the antimony estimation, the white metal is dissolved in hydro-
chloric acid and potassium chlorate, the solution decolorized by means
of stannous chloride, diluted, and reoxidized by a .stream of air.
The antimony is then titrated Avith potassium bromate, the bleaching
of methyl-orange being taken as the end-point. — C. H. D.
Zinc, Electrometric Titration of. — The electrometric method is
favourably compared with the fcrro-cyanide method by F. R. v.
Bichowsk}". J The use of internal or external indicators is obviated ;
the time taken for the determination is one-third that of the older
method ; and the electrometric end-point is unaft'ected by the colour
af the solution, by the lighting of the laboratory, by the amount of
acid or neutral salts present ; by iron, lead, manganese (up to 50 mg.)
Dr small amounts of copper and cadmium, all of which (except lead)
[lave marked effects in the other method, especially on the uranium
?nd-point.
The apparatus required, which is cheap and simple, is described,
ilso the details of the process. Using this method, the prehminary
* Zeilschrijl fiir angeicandte Cliemie, 1917, vol. xxx. p. 240.
t Ghemical News, 1917, vol. cxvi. p. 235.
J Journal of Industrial and Engineering Chemistry, July 1917, vol. ix. p. 668.
276 Abstracts of Papers
operations for the purification of the ore lose their customary
importance.
The two electrodes (platinum and calomel) are dipped in the beakei'
containing the solution to be analyzed, which should be hot, should i
contain at least 10 per cent, strong HCl, but no free oxidizing agents 1
nor more than a trace of cadmium. By adjusting the slide of a slide -
wire resistance, the pointer of a galvanometer is brought to zero and
the titration should then be begun.
As the addition of ferro-cyanide slowly proceeds, the pointer will
swing slowly until the end-point is reached. The ferro-cyanide is
added drop by drop until one drop causes a sudden very large but
permanent deflection. This is the end-point.
The methods in use for determination of zinc in ores as used by
the New Jersey Zinc Co., and by the American Zinc. Lead Smelting
Co., are described in detail. — F. J.
Zinc, Sampling of. — The methods adopted by the Hong Konsj;
Government for the sampling and analysis of zinc from the Yunnan
mining district are described by F. Browne.* Every tenth slab is
drilled, and the drillings are melted down in an iron ladle under palm
oil. Filings are taken from the clean ingot, 1 grm. dissolved in hydro-
chloric acid, and the solution titrated bv Parrv's method. — C. H. D.
U.—PHYSICAL AND MECHANICAL TESTING.
Brinell Hardness Tests. — An ingenious machine for making Brinell
tests is described by Guillerj\| In the ordinary test, a long time
is required to produce an impression of the full depth in steel, and
with the usual time of ten seconds, the diameter of the impression
is too small by an amount dJ). By making the load somewhat larger
than that prescribed for the test, this may be compensated for, the
relation being
(/P _ 2dp
3(KX) D
the normal load being 3000 kg.
The pressure is transmitted to the ball by a frictionless hydraulic
piston. The pressure is limited by a valve, consisting of a sphere
on a conical seating, held down by springs, the length and tension
of which may be regulated. The apparatus is adjusted by trial until
it gives the same diameter of impression for two speeds of loading
dift'ering in the ratio of 1 : 30. It is then in adjustment for all inter-
mediate speeds. Six hundred tests may be made in an hour. — C. H. D.
* Chemical News, 1918, vol. cxvii. p. 1.
t Comptes rendus, 1917, vol. clxv. p. 468.
Methods of Analysis, Testing and Pyrometry 111
The Biinell method for testing hardness is described by " Fairfax,"*
the operation of preparing the test-specimen being noted as of great
importance. PoHshing of samples in the lathe leaving a sm'face
covered with tool marks in concentric circles is especially condemned,
such marks rendering it difficult to take correct measm'ement of the
ball impression under the microscope. The following scale of loads
is recommended :
Load, 3000 kilos, when H = 100 and upwards
,, 1000 „ „ = 30 to 120
500 „ „ = 12 to 36
[In a table of typical BrincU hardness numerals, copper is given
a higher hardness number than Admiralty bronze. A correction is
necessary here. — Abstractor.]
The method of carrying out a Brinell hardness test in an ordinary
vertical testing machine arranged for testing in compression is de-
scribed by M. Waters. I The method is not so rapid nor so convenient
as by using the machines specially made for Brinell testing, but the
values are quite as accurate.
Another simple method, though less accurate, is to place the ball
between the test-piece and a standard piece of known Brinell hardness
and to squeeze in an ordinary bench vice. The hardness numerals
will be inversely proportional to the depths of indentations, and the
hardness of the unknown piece may be calculated by the formula
'- t
where
H = hardness numeral of standard piece.
■h — ,, ,, of piece under test.
l'^ — depth of ideutation of standard.
/ — ,, ,, of piece under test.
Depths of indentation may be measured with the micrometer,
first measuring with ball in indentation and then with ball resting
on surface. Difierence in readings gives depth of indentation. The
use of the auto-punch is noted.
The more important features of the standard method of Brinell
testing are described.*— F. J.
Hardness, Testing o£. — The general subject of hardness tests is
discussed by J. W. Craggs.J The usual forms of apparatus are
described, including the Pellin test, in which a steel ball is attached
to a vertical heavy bar, which is raised and held in position, and then
allowed to fall from a known height by means of an electro-magnetic
release. The sclerometer is the most useful instrument for measuring
penetration hardness, and the Saniter test for abrasion hardness. The
* Mechanical World, March 15, .1918, vol. Ixiii. p. 127.
t American Machinist, March 2, 1918, vol. 48, p. 8E.
X Journal of the Society of Chemical Industry, 1918, vol. xxxvii. p. 43.
278 Abstracts of Papers
sources of error in Brinell tests, due to coarseness of grain, are indicated,
and a series of tests with hardened nickel-chrome steels is given. In
the latter, the Brinell hardness was found to be the same for very
different rates of quenching, and the scleroscope numbers varied very
little, although the behaviour of the steel towards a file or towards
glass exliibited wdde variations. — C H. D.
Impact Testing Methods. — ^Descriptions arc given of the Izod
Charpy, Guillery, and drop-hammer systems of impact testing bj
M. M. W.,* the article being clearly illustrated. The Amsler anc
Fremont methods of measm-ing the energy absorbed in breaking speci-
mens by the drop-hammer are also described.
In some general remarks, the waiter states that the apparent dis-
crepancies between the impact and static tensile methods of testing
are now recognized as showing the two methods as being complementary
to one another, the impact test revealing conditions which the static
tests do not detect.
E^ddence has been brought forward by various experimenters
to show that this is due more to the efEect of the notch in locahzing
deformation and fracture than to the difierence in the rates at which
fracture takes place.
The influence of the shape and size of notch on the results is dis-
cussed. Schiile and Brunner have attempted to eliminate the in-
fluence of depth of notch by expressing the energy in terms of the
strained volume.
The system of forces acting on a Charpy specimen is analyzed,
the character and intensity of these stresses being diagrammatically
shown.
The work of Guillet and Revillon in experiments carried out to
investigate the variation of the impact figure with variation of tempera-
ture is summarized. — F. J.
Test-Bars in Non-Ferrous Alloys. — C. Vickers f states that no one
type of test-bar is suitable for all the non-ferrous alloys, some of which
give the best results in a cast-to-size bar, whilst others give the best
results when the lowest cast side of a heavy mass of metal is taken
for test. Test-bars are not regarded as representative of castings, great
importance being attached to the extent to which internal shrinkage
is made good by adequate feeding. Thus a casting may be unsound
through inadequate feeding, whilst a test-bar in the same mould may
be sound through adequate feeding.
The test results may be reversed in the case of some metals, e.g.
aluminium, which may give good castings but unsatisfactory test-
bars. The temperature required to produce satisfactory thin castings
may be too high for the thicker test-bar, which will give inferior tests
* Machinery, January 31, 1918, vol. xi. p. 477.
t Foundry, August 1917, vol. xlv. p. 322. |
Methods oj Analysis, Testing and Pyrometry 279
owing to the slow rate of cooling. Fine-grained castings of copper-
tin alloys exhibit external shrinkage to a greater extent than coarse-
grained castings, in which the large crystals constitute a skeleton
framework showing little external evidence of shrinkage, but which
show internal shrinkage owing to the molten metal in the interior of
the casting being insufficient in quantity to completely fill the vacant
places between the skeleton crystals. Such a casting exhibits lemon-
coloured spots at the fracture of a test-bar, is comparatively weak and
unable to withstand hydrauHc pressure. The effect of gating on the
soundness of test-bars is discussed at length, various methods being
illustrated and the corresponding test results tabulated. The results
given in Table I. relate to cast-to-size test-bars.
Table I.
Heat Ko.
Ultimate TensDe
Strength. Tons
per Sq. In.
Yield Point.
Tons per
Sq. In.
Elongation per
Cent, in 2 In.
Reduction of
Area per Cent.
161*
162 t
J 37-8
t 371
< 37-8
1 37-0
16-05
14-85
14-72
14-35
20-5
23-5
20-5
200
19-8
23-7
19-6
19-4
Analysis (approximate) ;
Copper
Zinc
Manganese
Aluminium
Iron
Tin
Per Cent.
57-73
40-45
0-08
0-64
107
003
The difficulty presented m " intercrystalline feeding " can only be
overcome by means of the hydrostatic pressure exerted by tall sprues
and risers of sufficiently large diameter to prevent the metal they
contain from freezing before the casting cools. The author prefers
to attribute porosity in cast bronze rather to insufficient feeding than
to dissimilar contraction coefficients of the structural constituents.
The keel-block method for making manganese-brass test-bars is
described. — F. J.
Testing of Sheet Brass.— C. H. Davis J has conducted an investiga-
tion with the object of obtaining a rapid, satisfactory, and comparative
method of testing sheet brass. Comparison tests have been made
between the widely used tensile strength, scleroscope, and Brinell
tests, and the more recently introduced ductihty, or cupping test.
The tests were made on identical or adjacent pieces of sheet^ brass,
* All new copper. t 50 per cent, scrap copper.
X Proceedings of the American, Society for Testing Materials, 1917, vol. xvii. p. 165.
280 Abstracts of Papers
specially gauged and rolled, so that the percentage reduction by
rolling was accurately known.
Complete data are given for one of the four brasses tested, to
illustrate the methods employed, and to give the comparative value
and limits of each method of testing. The scleroscope and Brinell
methods are found to be unsatisfactory on thin metal. The Brinell
method is satisfactory and comparative on thick metal. Scleroscope,
Brinell, and tensile strength tests do not vary appreciably with the
thickness of the metal. The ductility tests do vary with the thickness
of the metal, and therefore demonstrate in a practical way the drawing
value of any metal of any gauge, at the same time giving evidence of
the grain size and of imperfections in the metal.
It is concluded that for thin metal a cupping test is most satis-
factory, while for thick metal the Brinell test should be used. — D. H.
Ill.—PYROMETBY.
Eutectic Alloys in Pyrometry. — The use of eutectic alloys in deter-
mining fixed points in pyrometry is recommended by C. P. Steinmetz.*
The freezing point of Wood's metal, for example (the quaternary
eutectic of lead, tin, bismuth, and cadmium), is little affected by wide
variations in the proportions of the constituents, although the presence
of a metal other than one of the four components is harmful. The
alloys have been used in determining the temperature at the rim of
a steam turbine alternator, the high speed of which made the attach-
ment of any pyrometer impossible. Small holes were drilled in the
rim, and plugs of various eutectics inserted. It could then be found
which of these had melted, and the temperature thus obtained. —
C. H. D.
♦ Journal of the American Chemical Society, 1918, vol. xl. p. 96.
( 281 )
FURNACES; FOUNDRY METHODS AND
APPLIANCES.
CONTENTS.
II. Foundry Methods aud Appliances ........ 283
FACE
I. Furnaces and Furnace Materials 281
I.—FUBNACES AND FUBNACE MATEBLALS.
Electric Furnace for Brass. — The Ajax-Wyatt furnace is described
and illustrated.* This furnace is of the closed-channel induction
type, so that when in operation a pool of molten metal exerts
hydraulic pressure upon the metal in the closed channel. This
channel constitutes the secondary loop of the current path.
Motion of the molten metal, and therefore circulation, is effected
chiefly by motor efiect, a phenomenon which is explained and is stated,
in spite of the presence of Joule efiect and pinch eft'ect, to be of prime
importance in starting and maintaining circulation of the metal.
There are two sizes,»30 kilowatt and 60 kilowatt, the smaller one
having a power-factor of 85 per cent, and pouring 300 lb. of metal
per heat, whilst the larger size has a power-factor of 72 per cent, and
pours 600 lb. per heat. The temperature of the molten metal averaged
1093° C.
The furnace is intended only for copper-zinc alloys containing
not more than 3 per cent, lead, the copper varying from 95 to 60.
Operation must be continuous.
An electric crucible furnace (the Ajax-Northrup) is also being
developed. — F. J.
Induction Furnace for Melting Brass. — ^In a paper read to the
Philadelphia Foundiymen's Association, Nov. 7, 1917, G. H. Clamer f
states that there is no single type of furnace best suited for meeting
all conditions. A furnace suitable for one alloy or for large units may
be unsatisfactory for another alloy or for small units. Continuous
melting may mean all the difference between profitable and unprofitable
working. Flexibility in operation, e.g. possibihty of changing eco-
* The Foundry, December 1917, vol. xlv. p. 514.
t American Machinist, February 23, 1918, vol. 48, p. 21.
282 Abstracts of Papers
nomically from one mixture to another, may be lacking in a furnace,
thus putting it at a disadvantage in competition wath the crucible
furnace. Caution therefore is urged in selecting electric fm'nafces for
melting non-ferrous metals.
In designing horizontal open-ring induction furnaces, two injurious
factors have to be guarded against, viz. pinch effect and low-power
factor.
Pinch Effect. — This interferes with the proper running of furnaces
for melting copper and brass, because, unlike steel, they .have a low
resistance and necessitate so much current that the pinch effect is
introduced. This condition occurs only in induction furnaces having
the molten secondary in a horizontal plane of the open channel type.
Low-Poiver Factor. — This results from having the molten secondary
some distance from the primary coil, thus preventing the interhnking
of the two coils by way of the lines of force.
In melting 60 : 40 brass in this type of furnace, the needles of the
instrument commence to kick just as soon as the bath has reached
the correct pouring temperature. Charges of turnings, &c., may be
fed rapidly, as there is no danger of sohdifying metal in the secondary
channels or in the lower portion of the bath. The furnace is noiseless,
cool on outside of jacket, and may be sealed so as to prevent oxidation.
Circulation of the metal is energetic, constant, and automatic. Several
million pounds of brass have been melted in the Ajax-Wyatt furnace,
even in the form of turnings, sawings, &c. — F. J.
Melting Furnaces. — ^In a paper which was read before the London
Branch of the British Foundiymen's Association, T. W. Aitken *
describes the cupola, crucible, and reverberatory types of furnace.
In the crucible type, preference is shown for the tilting furnace,
using coke as fuel, thus securing uniformity of heating and protec-
tion of crucible from the forced draught.
A disadvantage is the formation of clinker, thus obstructing passage
of blast and necessitating frequent stoppages for removal. Side-fired
furnaces using low-pressure air are therefore recommended, -but a
generous fuel-space should be allowed. In side-blown furnaces better
arrangements can be made for collecting molten metal in case of the
crucible breaking. Gas-fired furnaces give too localized a heat and a
flame which is too destructive to lining and crucible, but low-pressure
gas furnaces are suitable for metals and alloys of low melting point,
e.g. zinc and aluminium.
The cutting flame is also a great drawback to oil-fired crucibles.
The reverberatory furnace is noted as of use for special purpose.^,
the melting process being slow and the fuel-consumption high. The
atmosphere of the furnace, however, is under better control than that
of the cupola. For melting copper and its alloys, a smoky flame
♦ Mechanical World, February 8, 1918, vol. kiii. p. 64.
Furnaces ; Foundry Methods and A ppliances 283
(reducing) should always be used. For observation piirposes, the
furnace atmosphere may be cleared by opening the fire-doors, thus
temporarily obtaining an oxidizing flame. Continuous melting lowers
the fuel-consumption per " heat " to less than that of the pit-fije
crucible type. EUmination of crucibles further lowers the cost of
melting, but ladles must be specially hot to prevent cooling of metal
to too low a temperature for pouring. — F. J.
1L~F0UNDRY METHODS AND APPLIANCES.
Aluminium Castings, Production of. — The general casting properties
of aluminium and its alloys are dealt with by J. Gaunt * in a paper
to the London Branch of the British Foundrymen's Association. It is
stated that in America preference is shown for aluminium-copper
alloys over almninium-zinc alloys, owing to ease of casting and relative
freedom from " drawing."
Sound castings of the latter alloys are more easily produced by
the addition of 1 to 2 per cent, copper.
In the remelting of aluminium-zinc alloys, a decrease of aluminium
and increase in zinc is to be expected. An allowance of 2 per cent,
loss of aluminium should be made.
Melting. — Careless overheating results in porous, spongy castings,
and the use of a pyrometer is strongly recommended. No special
covering to the metal is recommended, the use of charcoal being
disapproved. Zinc chloride is recommended as a flux. Plumbago
crucibles are preferred to iron ones, the former giving a better quality
product.
Casting Temperature. — Keep's shrinkage -testing apparatus was
used for determining the varying amounts of shrinkage of bars poured
at varying temperatures. It was foimd that metal cast above 1300° F:
had less shrinkage, was less dense and more pervious to water under
pressure. The addition of 2 per cent, tin to an aluminium-copper
alloy (8 per cent, copper) conferred greater soundness than ■^'ithout.
Moulding. — Owing to the low specific gravity of aluminium, audits
consequent lower resistance to the passage of gases, castings will be
frequently " blown," unless precautions are adopted. The remedy
recommended is fight ramming of the sand. The use of dry sand moulds
is discouraged.
Shrinkage. — ^In removing cores so as to facifitate shrinkage, great
care in handfing the casting must be exercised, as the metal is very
fragile at high temperature.
Heavy risers are necessary for heavy sections, and chills should be
reserved for such parts as are not accessible for the placing of feeders*
* Mechanical World, April 13 and 20, 1917, voL bd. pp. 186 and 198.
284 Abstracts of Papers
Runners. — "Where the metal enters the moukl runners of gouge-
shaped sections should be used and a large number of in-gates spread
over the whole casting. Runners should be circular rather than
■\vedge-shape if running on the top of the casting, but running into
the side of the casting is preferable. Quick pouring directly down
the runner is recommended in order that the mould may be com-
pletely filled.
Cores. — A special form of core-box for large cores is described.
Core sand for green cores should be similar to that used for the mould,
but dry-sand cores should be of such a composition as not to interfere
with contraction. Suggested mixtures are :
(a) • (&) (c)
Core bind, 2 J per cent, by measure. Resin, 1. Flour, 1.
Sea sand, 97| ,, ,, Red sand, 2. Sea sand, 12.
Sea sand, 10. " Temper " w itli
molasses.
Ramming. — Jolt ramming machines are recommended. A dis-
advantage of these machines lies in the fact that the sand packs in a
downward direction and will not fill in underneath projections. Sug-
gestions are made for mitigating this difficulty. — F. J.
Briquetting o£ Non-Ferrous Scrap. — The preparation of hght metal
scrap by the method of briquetting is described by A. L. Stillman.*
The author describes briquetting as " a process of fabricating small
or tine materials, usually the breakage or wastage from large blocks
of the same nature, into large sizes more suitable for the purpose in
hand, the purpose involving the destruction of the production or
briquette as such, either b}^ useful consumption, or as a step in a melting
or reducing operation." In the manufacture of metal briquettes for
melting, binding material should not be used unless it acts also as a
liux. Binders, apparently harmless in themselves, frequently introduce
cumphcations. It is advisable to achieve the results by the application
of pressure alone.
The first eiiect of the pressure is to break up the particles, and to
cause a certain amount of interlocking to take j)lace, while the in-
cluded air is slowly expelled. With increase in the pressm-e, a certain
amount of "bonding" takes place between the particles, which the
author considers is due to the union of the individual metal chips under
the influence of what he describes as " skin-tension set up under the
influence of the high pressure."
Of fiist importance in the manufactme of briquettes is the ex-
pulsion of the included air. Sudden apphcations of force, as in hammer-
ing, result in the retention of small cavities filled with air under high
pressure, which air breaks out during the melting operation and causes
the disintegration of the briquette. The usual method of manu-
* 3'/»e Aldal Industry, 1918, vol. xii. (4), p. 63.
Furnaces; Foundry Methods and Appliances 285
factiire involves the use of a hydraulic press, operated slowly to get
rid of the included air. The author describes two types of Konay
press, manufactured by the General Briquetting Company, New York.
The larger type contains six moulds set in a turn-table which is rotated
under a powerful hydraulic press. Three moulds are submitted
simultaneously to different operations, while the other three are idle.
The succeeding operation brings these three moulds under the three
pistons. The maximum pressure is applied after practically all the
air is expelled., and reaches 33,000 lb. per square inch in 5-inch moulds.
It is held just long enough to ensure a permanent set to the briquette,
after which the finished product is ejected automatically by a liy-
draulically operated plunger. The machine delivers four briquettes
per minute, or, expressed in terms of brass, at least two tons per hour.
A smaller machine is also described.
The briquettes made by this process have a density of about 75 to
80 per cent, of the ingot metal, but tliis deficiency is to some extent
counterbalanced by the fact that they pack much more com-
pactly in the crucible than ingots. Melting tests with manganese
bronze cliips and briquettes show a melting loss of 22 '5 per cent, using
untreated chips, 18'8 per cent, using loose chips with a flux, and 8'5
per cent, using briquetted chips. In the case of aluminium, briquetted
chips containing 2 per cent, of ammonium chloride as a flux showed
a loss of 8"1 per cent, as against 13'8 per cent, in the case of loose
chips. Metal made from briquettes also showed better mechanical
tests than that made from the loose borings. — D. H.
Metal Melting. — ^In a paper read before the North-Western Section
of the Junior Institution of Engineers, W. Eawlinson * reviews the
methods. of production, properties, and uses of non-ferrous alloys for
engineers. A few factors underlying successful melting of alloys
are given. Preference is shown for the crucible furnace of the tilting
typo, owing to greater rapidity of melting, economy in labour and in
fuel and crucibles.
The uses of coke, oil, and gas fuel are discussed. With regard to
coke, it is stated that in well-designed furnaces, properly operated,
the following are possible actual working fuel consumptions :
VcT Cent.
Aluminium . . . . 25 to 28
Yellow brass . . . i;i to 14
<5un-metal . . . . 1.5 to 16
Copper 17 to 18
As regards oil fuel a good analysis would be : Carbon, 87 per cent. ;
hydrogen, 12 per cent. ; sulphur, 07 per cent. ; oxygen and nitrogen,
0-1 per cent.; ash, 02 per cent.; specific gravity, 0-85: B.Th.U.,
18,000 per lb. ; flash point, 80° C.
* Mechanical World, January 11, 1918, vol. Ixiii. p. 16.
286 Abstracts of Papers
As regards gas fuel, average gas consumptions are as follows :
Brass . . . 5 c. ft. per lb. metal melted.
Gun-metal . . . . 6 ,, ,, ,, „
Aluminium . . . 8 ,, ,, ,, ,,
Nickel SO „
F.J.
Oil Furnaces for Brass. — ^In an article dealing with oil furnaces for
brass, J. Horner * states that the primary advantage of such furnaces
is in the low consumption of fuel in the preliminary heating-up period,
which, moreover, is of short duration.
At the conclusion of a heat there is no waste of fuel, the temperature
is regular, no stoking, nor cleaning out of ashes, no large fuel storage
nor transport difl&culties.
The oil furnaces of the Morgan Crucible Co. are described and
illustrated. An important feature is the 'Salamander" pre-heating
ring, which protects the metal undergoing preheating from sulphur
rontamination, &c. Low-pressm-e burners with air at 12 oz. per sq.
in. (20-in. water-gauge) are used. For high temperatures high -pressure
burners are used in specially designed furnaces, and in these the oil is
completely atomized.
The oil residue from gasworks, or one of the many distillates of
petroleum, shale, creosote, or asphalt are suitable. Water should not
be present above 2 5 per cent., otherwise the heating value is impaired
and the crucible damaged.
Tilting furnaces of 350 to 450 lb. capacity are recommended for
large foundries, and "lift-out" furnaces (each furnace being built to
take from one to four crucibles, according to requirements) for small
foundries.
In the latter class crucibles from 30 lb. to 200 lb. capacity may be
used.— F. J.
Suggestions for Melting Brass. — The chief featmes of an address
by H. 6. Barrett t to the London Branch of the British Foundrymen's
Association are reviewed. It is claimed that the physical properties
of many non-ferrous alloys have now been ascertained by research,
so that engineers have now a choice which should be guided more by a
knowledge of the information available than by a mere name. Some
practical advice is given regarding the distinctive features of under-
poled, tough, and overpoled copper ingots.
How to test the' purity of tin by surface appearance, &c., is
described.
The difficulties of dealing with scrap of variable composition are
touched upon and useful practical details in the working of an air
furnace of 3000 lb. capacity are given.
* Mechanical World, May 11, 1917, vol. Ixi. p. 236.
tJThe Foundry, November 1917, vol. xlv. p. 495.
Furnaces ; Foundry Methods and Appliances 287
Suggestions are also made for remedying defects in metal due to
inclusion of oxides or dross.
Plaster of Paris and common salt are regarded as useful
fluxes. — F. J.
Use of Crucibles in Foundries. — The handling of crucibles in the
foundry is dealt with at some length,* the importance of exercising
special care in handling — not only to avoid accidents, but also to
ensure greater length of service — having, it is stated, been underesti-
mated in the past.
With the advent of graphite crucibles fewer accidents and much
longer service have resulted. In these crucibles graphite is the chief
constituent, a small amount of clay (German) being used as a binding
material and a little " fire sand " to give an open grain and increase
resistance to alternations of temperature. The use of old crucibles
ground up for adding to the mixture is not approved.
In spite of its efficiency, the graphite crucible is fragile, and work-
men should receive special instructions in careful handling.
Crucibles should be very carefully inspected for cracks and flaws
when first received. Those not rejected should be stored in a dry
place, e.g. the roof of a continuously operated coke-oven.
To anneal before use, crucibles should be slowly heated to 120° C.
and kept at that temperature until moisture has been completely
eliminated. If annealing has not been carried out by the makers
they should next be heated to a dull red heat for some hours and then
slowly cooled to 120° C. and taken for use at that temperature. Large,
thick-walled crucibles require higher temperatures and a longer soaking
period. Pinholes and fissures are due to heating too rapidly, A
No. 200 crucible should take ten hours in raising to 120° C, and should
soak for ten hours. Alligator cracks may be due to too much sulphur
in fuel or, in oil furnaces, to insufficient oil or too much steam. They
may be due also to careless charging of metal. Ingots should be
introduced carefully and loosely. If wedged or jammed expansion
■mW impose strains on the crucible wall. The use of tongs and shanks
seriously reduces the life of a crucible. As many as fifty heats may be
obtained in a tilting furnace, but only about fifteen on an average
in a furnace from which removal by tongs is necessary at every heat.
The use of tongs and the proper kind of tongs to use are discussed.
The reshaping of tongs is also described, and the necessity for remo^^ng
clinker before applying the tongs is pointed out. Buttons of metal
should never be left in crucibles, and ramming of fuel should be avoided
or carried out with the utmost care. — F. J.
♦ Foundry, August 1917, vol. xlv. p. 316.
( 288 )
ELECTRO-CHEMISTRY ; METALLOGRAPHY.
CONTENTS.
PAGE
I. Electro-Caiemistry 288
II. Metallography 290
l.—ELECTBO-CHEMISTBY .
Cerium, Production oS, by Electrolysis.^ — Experiments carried out
with tlie object of finding tlie proper conditions for manufacture of
ceriimi by electrolysis of the fused chloride are described by M. de Kay
Thompson.* The work of Hirsh is referred to as coming nearest to
what was desired. In his paper Hirsh gave a review of previous
investigations. f He made in all about 1-5 kg. of metal, the cerium
chloride used being dehydrated in hydrochloric acid gas to prevent
decomposition.
The author claims to have shown dehydration in an atmosphere
of hydrochloric acid to be unnecessary. The cerium chloride was
prepared by dissolving cerium oxide, obtained from the Welsbach
Company, in strong hydrochloric acid in earthenware vessels and
evaporating to dryness in enamel-lined kettles. The dehydrated cake,
which should not be more than about 1-5 cm. tliick, was broken
out of the kettles with a cold chisel and stored in air-tight jars. For
35 kg. of oxide 102 kg. of strong hydrochloric acid were required,
yielding 45"4 kg. anhydrous chloride, from which 22-7 kg. of cerium
can be made.
The determination of cerium content was made by precipitating
the cerium with alkali hydrate, filtering, washing free from chloride,
dissolving in sulphuric acid, and reducing to cerous sulphate with
hydrogen peroxide. Permanganate was then added till the excess of
peroxide was destroyed as shown by the end-point. The cerous sulphate
was then oxidized with an excess of potassium ferricyanide and the
ferrocyamde produced titrated with permanganate. The first satis-
factory run in which a compact nugget of metal was produced was
carried out in a cast-iron pot 7 '5 cms. deep by 6-8 cms. internal diameter
which formed the cathode. The anode was a graphite rod 2 cms.
diameter. The chloride was made from the oxide as above described,
* Metallurgical and Chemical Emjineering, September 1917, vol. xvii. (No. 5), pp. 213-215.
t Transactions of the American Electro-Chemical Socitty, 20 (1), 1911.
Elecfro-Chemisfry ; Metallography
289
but in this case dehydrated in an atmosphere of hydrochloric acid.
A current of 90 amps, at 14 volts was passed until the total ampere
hours was 882. A nugget of impure cerium weighing 310 grammes
was obtained at a current efficiency of 21 per cent. Experiments
on a larger scale are next described, in which it was discovered that
the temperature must not get too high and the electrodes must be
kept a certain distance apart.
Eventually, iron plumbers' pots, 21 5 cms. diameter at the top, were
used as cathode, and contact made by bolting on an iron strip by
means of a bolt and a hole in the bottom of the pot. Four 5 cm.
diameter anodes were used. The following particvdars of a run are
given in which two pots as above' described were worked in parallel :
No. 1.
No. 2.
Metal obtained
Ampere hours
Current efficiency .....
Chloride fed in .
Chloride left undecomposed
Kilowatt hours
Kilowatt hours per kg. metal .
4-75
8940
30 per cent.
21-3 kg.
11-5 „
941
19-6
5-48
10,000
31 per o»nt.
23-9 kg.
15-2 „
105
19-2
During the course of the experiments 34 kg. in all of metal were
obtained.
In conclusion, the following directions for electrolysis are given :
The electrolysis is best started by melting a little chloride in the
iron pot or in a graphite crucible, from which it can be poured into the
iron pot. The anodes should be hot, to prevent the salt from freezing
around them and insulating the current, when first immersed. The
fused chloride should be about 25 cm. deep, and the anode should dip
into it 1-7 cm. The voltage between anode and cathode should be
about 10, and the current for a pot with one 5-cm. anode will then be
between 250 and 300 amperes. If more anodes are grouped together,
the current carried by each should be somewhat less. The pots should
not be heat-insulated. As the metal builds up, the anode is raised
and chloride is added, either in sohd lumps or fused ; it interferes less
with the electrolysis to add fused chloride. The cerium can be poured
directly from the electrolyzing vessel, but in these experiments it was
allowed to cool, the pot was broken open, and the metal separated
from the chloride. This was remelted under sodium chloride and
cast into bars in Acheson graphite moulds.
The metal is always surrounded with a black material, considered
by the author to be a mixture of cerium chloride and finely divided
cerium. — S. L. A.
Electro-deposition of Nickel, the Influence of Super-imposed Alter-
nating Current on. — The desirabihty of using pure nickel anodes in
VOL. XIX. U
290 Abstracts of Papers
place of cast nickel anodes for electro-deposition — owing to the simul-
taneous deposition of iron on the cathode with nickel and the resultant
darkening of the deposit — ^is discussed by S. A. Tucker and H. G.
Loesch.* The authors thought that pure nickel anodes could be made
to corrode properly in ammonium sulphate solution without the addi-
tion of other chemicals by superimposing an alternating current on the
direct current during electrolysis. They therefore carried out experi-
ments to study the corrosion of nickel anodes in nickel ammonium
sulphate solution (1) when D.C. alone, (2) when both D.C. and A.C.,
and (3) when A.C. alone passed through the solution. The anodes
used were roughened cast nickel, smooth cast nickel, rolled nickel, and
electrolytic nickel. The cast nickel contained 6"10 per cent, iron, the
rolled nickel showed the presence of small amounts of carbon and iron,
whilst the electrolytic nickel contained 99 "8 per cent, nickel.
The conclusions to which the authors arrived were as follows :
(1) With direct current alone, corrosion at the anode decreases
with increase of current density.
(2) Alternating current superimposed on direct current greatly
increases the anode corrosion with all varieties of anode, and this effect
increases with the A.C. current density.
(3) The increased corrosion at the anode raises the current efl5.ciency
at the cathode, particularly with rolled nickel anodes.
(4) Corrosion in general, with direct current or with superimposed
A.C, is markedly affected by the mechanical nature of the metal.
(5) Alternating current alone has but shght corrosive effect at the
anode. — F. J. j.
Electrolytic Nickel-Plating of Aluminnm. — Although the nickel-
plating of iron, copper, zinc, and brass is easy to carry out, consider-
able difficulties are experienced with alimiinium, as the nickel does
not adhere satisfactorily. A new process is described "j" that consists in
first covering the aluminium with a thin layer of iron and then nickel-
plating the surface so formed.
The aluminium should first be cleaned in a solution of potash and
then dipped in lime-water, and then in a solution of potassium cyanide,
and lastly in a solution of iron and hydrochloric acid. This process
forms a permanent covering of iron that can be detected by the use of
an electro-magnetic balance. After washing the surface in clean water,
it may be nickel-plated with a current of 1 amp. sq. cm. at a voltage
of 2-5 volts in an electrolyte containing 3-5 g. of nickel chloride to 1 1.
of water, and the nickel is found to adhere very well to the surface.
* Journal of Industrial and Engineering Chemistry, September 1917, vol. ix. p. 841.
t Zeitschrift des Vereines DexUschtr Ingenieure, July 7, 1917.
Electro-chemistry ; Metallography 291
11.—METALL0GBAFHY.
Cooling Curves of Ternary and Quaternary Mixtures. — ^It has been
previously shown by Hanemann * that the ordinary cooUng curves
of binary mixtures (time-temperature) in some instances fail to indicate
the beginning or the end of solidification. With reference to this paper,
N. Parravoano and C. Mazzetti f point out that the same thing may
happen for ternary or quaternary mixtures, whenever the " liquidus "
curve (in the ordinary temperature-composition diagram) is very steep ;
that is, when the equilibrium temperature changes very rapidly with
the composition, so that at every temperature but little solid is sepa-
rated and little heat is evolved. By means of a geometrical method,
explained through five drawings, they show how such instances
may be foreseen from the study of the equilibrium diagram. More
especially if we have a ternary system (say, an alloy) of the substances
ABC, completely miscible both in the liquid and in the soUd state —
A having the highest, C the lowest melting point — it is shown by the
authors that for the mixtures, where A predominates, the beginning
of sohdification is well marked in the cooling curve, but not its end ;
for mixtures, where B predominates, on the contrary, the end and not
the beginning of sohdification is well marked ; while if all the three
substances are present in about the same proportion both the beginning
and the end of solidification are indistinct. — A. M.
* Zeitschrift fiir anorgunische Chemie, 90, 1914 (67).
t OazzeUa Ohimica Italiana, 1917, vol. 47 (1), pp. 133-143.
( 292 )
BIBLIOGRAPHY.
[Books marked with an asterisk, thus *, may be consulted in the Librarj'.]
Aluminium and its Congeners, including the Rare Earth Metals. Vol. iv. of a Text-
Book of Inorganic Chemistry. Griffin. (Price 155. net.)
Battle, J. R. The Lubricating Engineer's Handbook. Pp.333, 114 illustrations,
125 tables, and 2 charts. Philadelphia : J. B. Lippincott & Co . (Price £1. )
*C0LLrNS, W. F. Mineral Enterprise in China. 8vo. Pp. 308 + xi. London
1918 : William Heinemann. (Price 21s. net.)
♦GiTJA, M;, and C. Guia-Lollini. Combinazioni Chimiche fra Metalli. 6J x 9J.
Pp. 446, with 207 illustrations. Milan, 1917 : Ulrico Hocpli. (Price
12-50 lire.)
[An exhaustive treatbe on inter-metallic compounds. Contains scores of equilibrium
diagrams of the most important of these compounds. Includes copious references to
original sources of information, but excludes all reference to work pubUshed in The
Journal of the Institute of Metals.']
*GowLAND, W. Metallurgy of the Non-Ferrous Metals. Second Edition. Pp. 588
+ xxxi, and 217 illustrations. London : Griffin & Co., Ltd. (Price 25«.)
[Since the first edition of this book was issued in 1914 many notable improvements
in metallurgical practice which were then in inception have been brought to the practical
stage. In this new edition the author describes in detail the most important of these,
the metals chiefly concerned being copper, zinc, nickel, and gold. In revising and
bringing up to date the whole text the author has aimed at making his book " a
useful standard of reference, both to the student and the practical metallurgist," an
aim which he has been remarkably successful in achieving.]
Heath, G. L. The Analysis of Copper. Pp. 292. London, 1918 : McGraw
Hill Book Co. (Price 155.)
HiKSCHBERG, C. A. Compressed Air for the Metal Worker. Pp. 321, 294 illustra-
tions. New York: Clark Book Co. (Price 15s. net.)
*Metal Statistics, 1918. Edited by C. S. J. Trench and B. E. V. Luty. Eleventh
Edition. New York, 1918 : American Metal Market Co.
[The volume contains statistics of tonnages and prices of copper, tin, lead, spelter,
aluminium, antimony, silver, and other metals, and includes typical tin analyses,
descriptions of commercial forms of aluminium and other information of interest to
engineers and metallurgists.]
*PiLCHEB, R. B., and Butler- Jones, F. What Industry owes to ChemiecU Science.
Pp. 150. London, 1918: Constable & Co. (Price 3s.)
[The authors show by examples how science has advanced the methods and pro-
cesses of production and has laid the foundation for the establishment of new manu-
factures. The subject of minerals and metals is given pride of place, constituting
chapter i., in which are given brief accounts of the metallurgy of copper, lead, sodium,
aluminium, magnesium, molybdenum and tungsten, chromium, thorium, vanadium,
gold, and the metals of the platinum group. Other chapters deal with coal and coal-
gas and refractory materials. A valuable introduction to the work is contributed
by Sir Qeorga Beilby.]
Bibliography 298
*Quin'a Metal Handbook and Statistics, 1918. Compiled by L. H. Quin. London :
Metal Information Bureau, Ltd. (Price 35. 6d.)
[The war has made further inroads upon the statistical details formerly available
regarding metal resources and the distribution of supplies. Germany suspended
publication of oflBcial returns of imports and exports on the outbreak of war. Belgium
followed suit, and France ceased publication at the end of 1916, while in 1917 British
returns were so revised and emasculated as to have lost much of their former value.
The United States figures reach Great Britain spasmodically and are very belated,
while there is great delay in the issuing of returns of many of the neutral countries,
and greater delay still in obtaining them. Nevertheless, the present issue of the Hand-
book contains as complete details as can be gathered, and embodies, moveover, much
entirely new matter.]
Searle, Alfred B. Refractory Materials, their Manufacture and Uses. 8vo.
Pp. 444, illustrated. Philadelphia, 1917 : J. B. Lippincott Co.
Webb, S. The Works' Manager of To-Day. London : Longmans. (Price 3«. 6d.)
( 294 )
SUBJECT INDEX.
A.
Abbreviations, use of, 228.
Accounts for 1917, 12.
AcKTYLENE, action on metals, 232.
Admiralty Aih Seevice, representative of, on Corro.sion Reeoarch Com-
mittee, 6.
Admiralty, representative of, on Corrosion Research Committee, 6.
representatives of, on Nomenclature Committee, 7.
Allotropy of bismuth, 236.
Alloy, swelling of zinc, die-castings, 259. •
Alloys, acid-resisting, 250.
aluminium, 267.
brass-rolling mill, 257.
coal-gas as a fuel for the melting of non-ferrou.s, 3.
electrolytic preparation of pyrophoric, 256.
eutcctic, in pyrometry, 280.
lead-tin-antimony, 36, 151-154.
nomenclature of, 227.
properties of, 2.50.
relationship between hardness and constitution in the copper rich
aluminium-copper, 36, 55-122.
surface tension and cohesion in metals and, 3.
test-bars in non-ferrous, 278.
of titanium, 264.
Aluminium alloys, 267.
annealing of, 36, 221-224.
the effects of heat at various temperatures on the rate of softening of
cold-rolled .sheet, 4.
— electrolytic nickel-plating of, 290.
industrial uses of, 256.
production of, by electrolysis : a note on the mechanism of the reaction, 3.
production of, castings, 283.
use of, 232.
Aluminium-bronze, 250.
die-casting of, 36, 123.
hardening of, 250.
ALUMiNiUM-corPEU, heat treatment of 10 per cent., 252.
relationship between hardness and constitution in the copper-rich alloys,
36, 55-122.
Subject Index 295
ALTTMisrirrM selenides, 251.
AliUMIXIXJM TEIXURIDES, 251.
Analysis of antimonial lead, 268.
of brass or bronze and babbitt metal, 268.
methods of, 267.
of " nichrome," 270.
of phosphor-zinc, 271.
volumetric method for, of phosphor-tiu, 271.
of white metals, 275.
Annealing of aluminium, 30, 221-224.
of metals, 233.
Annual General Meeting, 1.
Antimonial lead, analysis of, 268.
Antimony selenide, 252.
Auditor, election of, 29.
Authors, notes for, on preparation of papers, 227.
B.
Baronetcy conferred on member, 8.
Beilby Prize Committeb, members of, 7.
Birmingham local section, annual report, 225.
meetings of, 8.
membership of, 8.
Bismuth, allotropy of, 236.
Board of Scientific Societies, appointment of representative on, 9.
Board of Trade, representative of, on Corrosion Research Committee, 6.
Brass, analysis of, or bronze and babbitt metal, 268.
a comparison screen for, 4.
copper alloys, and bronzes, 225.
electric furnace for, 281.
the general properties of stampings and chill castings in, of approximately
60 : 40 composition, 3.
— induction furnace for melting, 281.
— inspection of, and bronze, 253.
— note on machining properties of, 3.
— oil furnaces for, 286.
— suggestions for melting, 286.
— testing of sheet, 279.
use of term, 227.
Brass condenser tubes, specifications for, 263.
Brasses, experim^jnts on the fatigue of, 4.
Brass-roltjng mux alloys, 257.
Bridge constbuction, bronzes for, 259.
Brinell hardness tests, 276.
Briquetting of non-ferrous scrap, 284.
British Electrical and Allied Manufactitrers' Association, representatives-
of, on Corrosion Research Committee, 6.
296 Subject Index
Bronze, analysis of brass or, and babbitt metal, 268.
inspection of brass and, 253.
investigation on unsound castings of Admiralty (88 : 10 : 2); its cause and
the remedy, 36, 155.
and some of its modifications, 8.
use of term, 228.
Bron7.es for bridge construction, 259.
copper alloy.=;, brass and, 225.
0.
CiDMiUM. detection of, 260.
iodonetric detertniuation of, 274.
separation of zinc from, 274.
Cadmtpm sklknide, 252.
Calotum, electrical properties of, 237.
Canada, nickel in, 263.
Castings, investigation on unsourd, of Admiralty bronze (88 : 10 . 2) ; its cause
and the remedy, 36, 155.
Cericm, production of, by electrolysis, 288.
Chromic auid, action of, on silver, 245.
the use of, and hydrogen peroxide as an etching agent, 4.
CoAL-iAS as a fuel for the melting of non-ferrous .alloys, 3.
Commanders op thk Order of the British Empire, members become, 9.
Committees appointed, 5-7.
members of, 5.
officers of, 5.
Companions of the Bath, members become, 9.
Condenser tcbing, corrosion of, 264.
CO-OPKRATIVB LABORATORIES, 225.
Copper, hardness of hard-drawn, 237.
iodometry of, 269.
modulus of elasticity of electrolytic, 237.
Copper alloys, brass and bronzes, 225.
Corrosion, 264.
of condenser tubing, 264.
of lead roofing, 265.
selective, of Muntz metal, 265.
Corrosion fond, accounts of, 1915-1916, 14.
1916-1917, 13.
CoBBOSiON Research Committeh, grants to, 8.
members of, 6.
work of, 43.
Crucibles, use of, in foundries, 287.
Crystal analysis by X-rays, 238.
Crystal structure and X-rays, 248.
Crystals, production of, 239.
Cdpferron as a reagent, 269.
CaEVES, cooling, of ternary and quaternary mixtures, 291.
Subject Index 297
D.
Dentai. amalgam as an absorbent for mercury, 252.
Diagrams, lettering of, 229.
use of, 229.
DiB-CASiTN'G of aluminium- bronze, 30, 123.
swelling of zinc alloj', 259.
DiLATOMSTER, recording differential, 272.
E.
Electiox of auditor, 29.
of members, 21-28.
of officers, 19.
of students, 24, 28.
Electro-chemistry, 288.
Electrode, lead standard, 242.
Electrolysis, aluminium production by ; a note on tte mechanism of the reac-
tion, 3.
Electrolytic zinc, 249.
Emission of X-rays, 248.
Emulsions and suspensions with molten metals, 239.
Etching- AGENT, the use of chromic acid and hydrogen peroxide as an, 4.
Eutectio alloys in pyrometry, 280.
Expansion of tungsten, 247.
F.
Fatigue of brasses, experiments on the, 4.
Finance and General Purposes Committee, members of, 5.
Foundries, use of crucibles in, 287.
Foundry appliances, 283.
methods, 283.
Fresh-water Corrosion Research Committee appointhd, 8.
Furnaces, 281.
coke-fired, 3.
electric, for brass, 281.
an electric resistance, for melting in crucibles, 4.
fuel economy possibilities in brass-melting, 4.
induction, for melting brass, 281.
materials, 281.
melting, 282.
— metal melting in a simple crude oil, 4.
— a new producer gas-lired crucible, 4.
— oil, for brass, 286.
298 Subject Index
Q.
Gas-fibing, principles aud methods of a new Bystem of, 4.
MELTING, high-pressure, 3.
Gold and platinum, colloidal, 240.
GovEKSMF.NT, offices taken over by, 5.
Grain size, 36, 145-148.
of metals, 240.
H.
Hahdbning of aluminium bronze, 250. •
Hardness of hard-drawn copper, 237.
testing of, 277.
Heat, effect of, at various temperatures on the rate of softening of cold-rolled
aluminium sheet, 4.
TREATMENT of 10 per ccut, aluminium-copper, 252.
Honorary Treasurer, report of, 17.
Honours received by members, 8, 9.
Hydrogen peroxide, the use of chromic acid and, as an etching agent, 4.
I.
Illustrations, use of, 228.
Inaugural address by president.. 33, 37-54.
Increased Membership Committee, members of, 7.
Industrial applications, 256.
uses of aluminium, 256.
Institute of Marine Engineers, representative of, on Corrosion Research
Committee, 6.
Institute of Metals, giowth of, 37—40.
Insiitutton of Electrical Engineers, representative of, on CJorrosion Research
Committee, 6.
on Nomenclature Committee, 7.
of Engineers and Shipbuilders in Scotland, representative of. on
Nomenclature Committee, 7.
— of Mechanical Engineers, representative of, on Corrosion Research
Committee, 6.
on Nomenclature Committee, 7.
of Milling Engineers, question of setting up building with, 5.
of Mining and Metallurgy, question of setting up building with, 5.
of Naval Architects, representative of, on Corrosion Research Committee, 6.
on Nomenclature Committee, 7.
Investment account, 12.
loDOMETBY of coppcr, 269.
Iron, separation of, from lead, 270.
AND Steel Institute, question of setting up building with, 5.
Italy, metallurgy in, 260.
Subject Index ?.99*
J.
JouENAL, sales of, 8, 40.
Knighthood conferred on member, 8, 9.
Kkights Commander of the Bath, members become, 9.
of the British Empire, members become, 9.
L.
Laboratory, relation between workshop and, 225.
scope of the works, 225.
Lead, separation of iron from, 270.
standard electrode, 242.
roofing, corrosion of, 265.
Lead-tin-antimony alloys, 36, 151-154.
Library and Museum Combhttee, members of, 6.
Lloyd's eeoisteb, representative of, on Corrosion Research Committee, 6.
M.
Manganese, colorimetric estimation of, 270.
May Lecture, 4.
Member of the Order of the British Empire, member becomes, 9.
Members of Committees, 5-7.
deaths of, 3.
election of, 21-28.
fallen in war, 53.
number of, 2. ,
Membership of Birmingham Local Section, 225.
changes in, 2.
increase of, 41-43.
MsRcrRY, dental amalgam an absorbent for, 252.
Metallography, 290.
Metallurgists, physico-chemical data for, 244.
Metallurgy in Italy, 260.
of titanium, 247.
Metal melting, discussion on, 3.
• as practised at the Royal Mint, 3.
in a simple crude oil furnace, 4.
Metals, action of acetylene on, 232.
annealing of, 233.
the effect of great hydrostatic pressure on the physical properties of, 4-
emulsions and suspensions with molten, 239.
grain size of, 240.
the hardening of, by work, 8.
ideals and limitations in the melting of non-ferrous, 4.
800 Subject Index
Metals, properties of, 232.
quenching of various, in water, 245.
surface tension and cohesion in, and alloys, 3.
thermo-electric properties of fused, 239.
vapour pressure of liquid, 242.
vapour pressure and volatility of several high boiling point, 247.
X-ray examination of, 243.
Metal-spraying trocess, 261.
Mktal trades, application of pyrometry in, 225.
the scientific spirit in, 225.
Muntz metal, selective corrosion of, 205.
N.
National Physical Laboratory, representative of, on Corrosion Research
Committee, 6.
" NiCHROME," notes on the analysis of, 270.
Nickel in Canada, 263.
colloidal, 243.
electrolytic behaviour of, 243.
the influence of super -imposed alternating cmrent on electro-deposition
of, 289.
PLATING, electrolytic, of aluminium, 290.
SILVER, the annealing of, 3.
Nomenclature committee, members of, 6, 7.
Non-ferrous alloys, test-bars in, 27vS.
SCRAP, briquetting of, 284.
North-East Coast Institution or Engineers and Shipbuilders, repiusenta-
tive of, on Nomenclature Committee, 7.
o.
Officers, election of, 19.
of Birmingham Local Section, 226.
of the Order of the British Empire, members become, 9.
Offices, change of, 5.
Optical indicator, researches made possible by the autograph load-extension. 4.
P.
Papers, form of, 227,
notes for authors on preparation of, 227.
Phosphor-tin, a volumetric method for the analysis of, 27L
Phosphor-zinc, analysis of, 27L
Photo-electric effect, 244.
Physico-chemical data for metallurgists, 244-
Plates, use of, 228.
Platinum and gold, colloidal, 240.
■ microchemical detection of, 272.
Subject Index ^V
Platinum, ELECTRODEg, aubatitutos for, 272.
substitutes, 254.
Properties of alloys, 250.
electrical, of calcium, 237.
of metals, 232.
of solid solutions, 246.
thermo-electric, of fused metals, 239.
PuBUCATiox COMMITTEE, members of, 5.
Pyrometry, application of, to metal trades, 225.
eutectic alloys in, 280.
PYRoniORic alloys, electrolytic preparation of, 25fl.
Q.
Quaternary mixtures, cooling curves of, 291.
QuENCHiNO of various metals in water, 245.
R.
Receipts and Payments Account, 12.
Refractories Research and Standards Committee, representatives appointed
to, 9.
Report of Birmingham Local Section, 225.
of Couacil for 1917, 1-21.
Research into corrosion of non-ferrocs metals, accounts of, to 1916, 16.
1916-1917, 15.
Roll op members, 2.
S.
Scientific and industrial research committee, members of, 6.
Silver, action of chromic acid on, 245.
SociETYOF CHEMICAL industry, representative of, on Nomenclature Committee, 7.
Sodium, preparation of, 245.
Solid solutions, properties of, 246.
Space-lattice of tungsten, 247.
Specifications for brass condenser tubes, 263.
Standards of Non-Ferrous Metals and Alloys Committee, members of, 7.
Students, election of, 24, 2S.
Sulphide precipitates, separation of, 274.
Suspensions and elmulsions with molten metals, 239.
T.
Tables, ase of, 228.
Technical training, 47-53.
Ternary mixtures, cooling curves of, 291.
Test-bars in non-ferrous alloys, 278.
Testing of hardness, 277. ■ •
impact, 278.
302 Subject Index
Testing, physical and mechanical, 270.
of sheet brass, 279.
Thermo-electric effects, 246.
Thermostat, further notes on a high temperature, 4.
Tin, separation of, and tungsten, 274.
Titanium, alloys of, 264.
metallurgy of, 247. < \
Treasurer's report, 11-16.
Tungsten, expansion of, 247.
separation of tin and, 274.
space-lattice of, 247.
valuation of, powder, 275.
V.
Vapour pressure of liquid metals, 242.
and volatility of .several high boiling point metals, 247.
Volatility, vapour pressure and, of several high boiling point metals, 247.
w.
War OmcE, representative of, on Nomenclature Committee, 7.
White metals, method for analysis of, 275.
Workshop, relation between the laboratory and, 225.
X.
X-RAYS, crystal analy.sis by, 238.
and crystal structure, 248.
emission of, 248.
e.<camination of metals, 243.
z.
ZiNO, electrolytic, 249-
electrometric titration of, 275.
sampling of, 276.
separation of, from cadmium, 274.
ALLOY, die-castings, swelling of, 259.
SELENIDE, 256.
303
Name index.
A.
AiTKF.N, T. W., abstract of paper by, 282.
Allday, Percy William, elected member, 21.
Allen, W. H., member of Publication Committee, 5.
Anueeson, R. J., abstract of paper by, 247.
Note " On the annealing of aluminium," 36, 221 ; microscopy, 222 ;
results of annealing, 223. — Di/iCu.is{on : D. Hanson, 224 ; A. G. C. Gwyer,
224.
Andrew, Dr. J. H., on the relationship between hardness and constitution
in the copper rich aluminium-copper alloy.«<, 114.
Antisell, Frank Linden, elected member, 21.
AoKi, T., abstract of paper by, 251.
Akchbutt, L., elected member of council, 19.
member of Corrosion Research Committee, 6.
Publication Committee, 5.
— Scientific and Industrial Research Committee, (5.
S. L., working on preparation of abstracts, 231.
Arnold, Hans, abstract of paper by, 261.
Arnon, abstract of paper by, 252.
AsTBXJRY, Harry, elected member, 21.
Auditor. Sei Poppleton, G. G.
Barclay, W. R.—
PajJer on " Relation between the laboratory and the workshop," 225.
Barker, T. V., summary of paper, 248.
Barrett, H. G., abstract of paper by, 2S6.
Barwell, C. H., past chairman of Birmingham Local Section, 220.
Battle, J. R., book by, 292.
Batty, Robert Bealc, elected member, 21.
Beilky, Sir George, chairman at Annual General Meeting, 1.
— Beilby Prize Committee, 7.
on Honorary Treasurer's report, 17.
introduces new president, 29.
proposes re-election of auditor, 29.
proposes vote of thanks to Honorary Treasurer, 18.
on Report of Council for 1917, 10, 11.
responds to vote of thanks, 32.
on retiring council, 20.
vote of thanks to, 31.
304 Name Index
Bell, Thomas, becomes Knight Commander of the British Empire, 9.
Benedicks, C, abstract of paper by, 246.
Bengough, Capt. G. D., moves vote of thanks to retiring council, 19.
Bentley, Harry, elected member, 24.
BiCHOWSKY, F. R. v., abstract of paper by, 275. '
Biles, Professor Sir John Harvard, elected member, 24.
BiLL-GozzARD, G., on committee of Birmingham Local Section, 226.
BoEDDiCKER, G. A., elected vice-president, 19.
member of Finance and General Purposes Committee, 5.
Nomenclature Committee, 6.
Publication Committee, 5.
past chairman of Birmingham Local Section, 226.
Bolton, T., member of Scientific and Industrial Research Committee, 6.
Booth, George William, elected member, 24.
Bradshaw, James Henry Davis, elected member, 24.
Br.«d, Arthur Forbes, elected member, 21.
Brainin, abstract of paper by, 248.
Brame, J. S. S., abstract of paper by, 265.
Briggs, John Waddingtou, elected member, 24.
Brook, G. B., on coal-gas as a fuel for the melting of non-ferrous alloys, 3.
on an investigation on unsound castings of Admiralty bronze (88 : 10 : 2) ;
its cause and the remedy, 188.
Brown, Hugh, elected member, 22.
J., abstract of paper by, 269.
becomes Commander of the Order of the British Empire, 9.
Browne, F., abstract of paper by, 276.
Brownsdon, Dr. H. W., on committee of Birmingham Local Section, 226.
DE Bruyn, C. a. Lobry, abstract of paper by, 243.
Bbydall, Robert Belhaven, elected member, 25.
BuTTERFiELD, J. C, death of, 3.
Butter- Jones, F., book by, 292.
o.
Carpenter, Professor H. C. H., on Beilby Prize Committee, 7.
chairman of Annual General Meeting, 1, 36.
of Committee on Increased Membership, 7.
Corrosion Research Committee, 6.
on die-casting of aluminium bronze, 138.
• on the effect of heat at various temperatures ou the rate of softening of
cold-rolled aluminium sheet, 4.
elected president, 19.
on grain size, 149.
on an investigation on unsound castings of Admiralty bronze (88 : 10 : 2);
its cause and the remedy, 36, 155. Practical considerations, 171. Summary
and conclusions, 174. — Discussion : Professor T. Turner, 176 ; J. Dewrance,
176; Commander C. F. Jenkin, R.N.V.R., 177; M. Thornton Murray, 178;
Professor C. A. Edwards, 181, 185; Dr. W. H. Hatfield, 182; F. Johnson,
182; Dr. W. Rosenhain, 184; A. Cleghorn, 187; H. H. A. Greer, 187;
Name Index 305
G. B. Brook, 188; Professor Turner, \m.—Beply to Diacusaion, 191.—
Communicalions : J. L. Haughton, 193 ; F. Johnson, 194 ; Dr. Percy
Longmuir, 194; W. E. W. Miilington, 196; H. S. Primrose, 204; William
Ram-say, 206 ; R. T. Rolfe, 208 ; H. T. Young, 2]2.—Repli/ io Communica-
tions: 212.
Cabpenteb, Profe.ssor H. C. H., member of Finance and General Purposes Com-
mittee, 5.
• of Publication Committee, 5.
of Standards of Non-Ferrous Metals and Alloys, 7.
presidential address by, 33, 37-54.
responds to vote of thanks, 35.
takes presidential chair, 30.
work of, 30.
Carter, George J., becomes Knight Commander of the British Empire, 9.
Cathcart, William Button, elected member, 25.
Chapple, Harold M., elected member, 25.
Chbvksard, p., abstract of paper by, 272.
Chikashige, M., abstract of papers by, 251, 252, 256.
Clamer, G. H., abstract of paper by, 281.
Clark, Robert MacFarlane, elected member, 25.
Sidney, elected student, 24.
Clarke, H. W., on committee of Birmingham Local Section, 226.
Claudkt, Frederic Herbert Bartemps, elected member, 25.
Clayton, Charles Yancey, elected member, 22.
Cleghorn, a., on an investigation on unsound castings of Admiralty bronze
(88 : 10 : 2) ; its cause and the remedy, 187.
CoHEK, Herbert Edward, elected member, 25.
Collins, W. F., book by, 292.
Collttt, B., abstract of paper by, 267.
CoMSTOCK, G. F., abstract of paper by, 250.
Cook, Maurice, elected student, 28.
CoRFiELD, J., death of, 3.
CoB3K, W. M., abstract of paper by, 250.
Cox, Ernest George, elected member, 22.
Cbaggs, J. W., abstract of paper by, 277.
Cuming, G., becomes Officer of the Order of the British Empire, 9.
D.
Dalbt, Professor W. E., lecture on researches made possible by the autograph
load -extension optical indicator, 4.
Darling, C. R., abstract of paper by, 239.
Davies, R. H., associate member of Birmingham Local Section, 226.
Davis, C. H., abstract of paper by, 279.
Debyb, p., abstract of paper by, 247.
Deer, G., death of, 3.
Dendy, E. E., becomes Commander of the Order of the British Empire, 9.
Desch, Dr. C. H., on Beilby Prize Committee, 7.
member of Nomenclature Committee, 6.
working on preparation of abstracts, 231.
VOL. XIX. X
806 Name Index
Dewranob, J., on Committee on Standards of Non-Ferrous Metala and Alloys, 7.
. on die-casting of aluminium bronze, 137.
— on an investigation on unsound castings of Admiralty bronze (88 : 10 ; 2j
its cause and the remedy, 176.
— member of CJomrcittee on Increased Membership, 7.
. — ■ Finance and General Purposes Committee, 5.
Library and Museum Committee, 6.
Scientific and Industrial Research Committee, 6.
seconds re-election of auditor, 29.
Dextek, William Allinson, elected member, 25.
DiCKiNSOK, Frederick Thompson, elected member, 22.
Dixon, Eng.-Gapt. R. B., R.N., becomes Companion of the Bath, 9s
DoDWELL, Albert Ernest, elected member, 25.
Donaldson, Thomas, elected member, 25.
Drtsdale, William, elected member, 25. '
D0NDAS, David, elected member, 25. '*'
DtTNLOP, Eng.-Lt.-Com. Samuel Harrison, elected member, 22.
B.
Easdalb, James, elected member, 25. '
EASTHorE, Thomas Wilmot, elected member, 25.
Eatov, Lt.-Col. Edmund, elected member, 22.
Edwards, Professor C. A., on die-casting of aluminium bronze, 134.
elected member of coimcil, 19.
. on an investigation on unsound castinge of Admiralty bronze (88 : 10 : 2) ;
its cause and the remedy, 181, 185.
on the relationship between hardness and constitution in the copper rich
aluminium -copper alloys, 101, 108.
seconds vote of th£nk3 for president's address, 34.
Elam, Miss C. F.—
Note on " An investigation on imsound castings of Admiralty bronze
(88 : 10 : 2); its cause and the remedy," 36, 155. Practical considerations, 171*
Summary and conclusions, 174. — Discussion: Professor Turner, 176; J'
Dewrance, 176; Commander C. F. Jenkins, R.N.V.R., 177; M. Thornton
Murray, 178 ; Professor C. A. Edwards, 181, 185 ; Dr. W. H. Hatfield, 182 ; F.
Johnson, 182 ; Dr. W. Rosenhain, 184 ; A. Cleghom, 187 ; H. H. A. Greer, 187 ;
G. B. Brook, 188 ; Professor Turner, 189. — Reply io Discussion, 191. — Com-
munications : J. L. Haughton, 193 ; F. Johnson, 194 ; Dr. Percy Longmuir, 194;
W. E. W. Millington, 196; M. Thornton Murray, 197 ; W. B. Parker, 198; H.
S. Primrose, 204 ; William Ramsay, 206 ; R. T. Rolfe, 208 ; H. J. Young, 212.
— i?ep/(/ to Communications : 212.
Ellis, Charles Edward, becomes Knight Commander of the Bath, 9.
Owen, William, on the general properties of stampings and chill castings
in brass of approximately 60 : 40 composition, 3.
note on a comparison screen for brass, 4.
note on lead-tin-antimony alloys, 36, 151-154.
note on machining properties of brass, 3.
Enstowb, Thomas Clement, elected member. 26.
Name Index 807
Ericson, E. J., abstract of paper by, 274.
EssLEMONT, A. S., becomes Commander of the Order of the British Empire, 9.
EvERED, Stanley, address by, 8.
address on co-operative laboratories, 225.
member of Committee on Increased Membership, 7.
past chairman of Birmingham Local Section, 22fi.
F.
Fahrenwald, F. a., abstract of pai)er by, 254.
Fegeley, a. H., abstract of paper by, 271.
FiFTELD, Albert F., elected member, 22.
Flinn, a. D., abstract of paper by, 253.
Ford, Benjamin, elected member, 25.
Fowler, Lieut-Col. Henry, becomes Knight Commander of the British Empire, 9;
FujiTA, M., abstract of paper by, 252.
G.
Garland, Richard Vernon, elected member, 22.
Garner, Joseph Richardson, elected member, 2
Garvin, abstract of paper by, 245.
Gaunt, J., abstract of paper by, 283.
Gemmell, John Zachariah, elected member, 25
Genders, John Boulton, elected member, 22.
George, Cecil Walter, elected member, 26.
Gewecke, J., abstract of paper by, 272.
Gibson, John, elected member, 26.
J. H., becomes Officer of the Order of the British Empire, 9.
Gilchrist, .\rchibald, elected member, 26.
J., death of, 3.
GiLLETT, H. W., abstract of paper by, 239.
GnxA, M., book by, 292.
Glazebrook, Richard T., C.B., made a knight, 9.
GooDcniLD, Charles, elected member, 26.
Goodenough, Francis William, elected member, 22.
Goodwin, Eng.- Vice -Admiral George G., becomes [Knight Commander] of the
Bath, 9.
elected member of council, 19.
member of Nomenclature Committee, 6.
proposes vote of thanks for president's address, 33.
Miss Winifred iL-iry Lenice, elected member, 22.
GowLAND, Professor W., book by, 292.
member of Publication Committee, 5.
Grabe, Alf. Gerhard, elected member, 22.
Grace, A. W., abstract of paper by, 239.
Gracie, Alexander, M.V.O., becomes Knight Commander of the British Empire, 9.
Grant, JohnH., elected member, 22.
Gravely, Capt. Julian Stuart, elected member, 26.
X2
308 Name Index
Gray, George Watson, elected member, 26.
James Thomas, elected member, 22.
Gbazebbook, Eng.-Lt. R., fallen in war, 53.
Geeathouse, L. H., abstract of paper by, 270.
Greeswood, H. C, on an electric resistance furnace for melting in crucibles, 4;
.1. Ncill.—
Paper on " The relationship between hardness and constitution in the
copper rich aluminium-copper alloj's," 36 ; summary of previous work
dealing with this subject, 55 ; materials used and analysis of alloys, 59 ;
preliminary experiments, 60 ; time of application of load in Brinell tests, 61 ;
mode of distribution of constitutents, 62 ; inclination of two oppoait^
surfaces of experiment, 64 ; thickness of specimen, 65 ; efEect of surface
finish as scleroscope tests, 66 ; efEect of varying load on Brinell number, 67 ;
summary of the preliminary experiments on the Brinell and scleroscope tests,
72 ; effect of quenching temperature on the hardness of alloys containing 9 to 16
per cent, aluminium, 73 ; time required to attain equilibrium in these alloys,
79 ; general types of hardness composition curves, 81 ; hardness of the
solid solutions, 83 ; hardness of the ^ solutions, 85 ; the a -f /3 conglomerates,
91 ; hardness of alloys quenched at 600" C after attaining equilibrium, 94 ;
summary and conclusions, 95; appendix, 99. — Discussion: Professor
C. A. Edwards, 101 ; Dr. W. Rosenhain, 103 ; Dr. 0. F. Hudson, 105 ;
Professor T. Turner, 106; Dr. W. H. Hatfield, 101.— Reply to Discussion,
108, 112. — Communications : Dr. J. H. Andrews, 114; J. L. Haughton, 117 ;
Dr. F. C. Thompson, 118. — R''.pl>/ to Communications : 120.
Greer, H. H. A., on an investigation on unsound castings of Admiralty bronze
(88 : 10 : 2): its cause and the remedy, 187.
Griggs, Arthur Robert, elected member, 22.
Guernsey, Rt. Hon. Lord, fallen in war, 53.
GuiA-LoLLisi, C, book by, 292.
G CILLERY, abstract of paper by, 276.
GULLIVEB, G. H. —
Note '• On grain size," 36, lin-liS.— Discussion : Dr. W Rosenhain, 149
Professor H. C. H. Carpenter, 149.
GwYER, A. G. C, on the annealing of aluminium, 224.
H.
Hadfield, Sir Robert, Bart., elected member of council, 19.
made a baronet, 8.
moraber of Publication Committee, 5.
Hagmaier. E. W., abstract of paper by, 268.
Haigh, B. Parker, on experiments on the fatigue of brasses. 4.
Ham, Capt. J. W., R.N., made Companion of the Bath, 9.
Hammond, Charles F., elected member, 22.
Hanson, D., on the annealing of aluminium, 224.
further notes on a high temperature thermostat, 4.
working on preparation of abstracts, 231.
Habbobd. F. W., becomes Commander of the Order of the British Empire, •».
Habdcasxle, Eng.-Com. Sydney Undercliffe, R.N., elected member, 26.
Name Index 309
Hartley, H., contribution to metal melting discussion, 3.
Habvey, L. C, on fuel economy possibilities in brass-melting furnaces, 4.
Hatfield, Dr. W. H., ou an investigation on unsound castings of Admiralty
bronze (88 : 10 : 2); it i cause and the remedy, 182.
on the relationship between hardness and constitution in the copj^r rich
aluminium-copper alloys, 107, 108.
Hauqhton, J. L., further notes on a high temperature thermostat, 4.
on an investigation on unsound castings of Admiralty bronze (88 ; 10 : 2);
its cause and the remedy, 193.
on the relationship between hardness and constitution in the coppper rich
aluminium-copper alloys, 117.
seconds vote of thanks to retiring council, 20.
Hawkes, Eng.-Com. Charles John, R.N., elected member, 26.
Hayward, Fred. Philip Finch, elected member, 26.
Heath, G. L., book by, 292.
Henderson, W. E., abstract of paper by, 242.
Henman, W. H., honorary secretary of Birmingham Local Section, 226.
Hering, Carl, on ideals and limitations in the melting of non-ferrous metals, 4.
Herriot, William Scott, elected member, 26.
Hildebrand, J. H., abstract of paper by, 242.
Hill, D. V., abstract of paper by, 245.
HiRSCHBERG, C. A., book by, 292.
Hirst, T. G., on die-casting of aluminium-bronze, 132.
HiTOSAKA, II., abstract of paper by, 252.
Hocking, W. J., on metal melting as practised at the Royal IMint, 3.
HODES, F., abstract of paper by, 275.
Hodgkinson, Professor W. R., abstract of paper by, 232.
becomes Commander of the Order of the British Empire, 9.
Hogg, T. W., death of, 3.
Holloway, G. T., death of, 3.
Holmes, H. N., abstract of pajjer by, 239.
HopivINS, S. M., honorary secretary of Birmingham Local Section, 226.
Hopkinson, F. a., death of, 3.
Horner, J., abstract of paper by, 286.
Howden, R., abstract of paper by, 275.
Hudson, Dr. 0 F., on the relationship between hardness and constitution in
the copper rich aluminium-copper alloys, 105.
seconds adopting of report, 11.
Hughes, A. L., abstract of paper by, 244.
G., elected member of council, 19.
member of Finance and General Purposes Committee, 5.
Nomenclature Committee, 6.
Hull, A. W., abstract of paper by, 238.
Hunter, Dr. George B., becomes Knight Commander of the British Empire, 9.
Summers, becomes Commander of the Order of the British Empire, 9.
Huntington, Professor A. K., acting Chairman of Scientific and Industrial
Research Committee, 6.
- appointed representative to Refractories Research and Standards-
Committee, 9.
310 Name Index
Huntington, Professor A. K., on:Bcilby Prize £!onimittee, 7.
chairman of Publication Committee, 5.
member of Corrosion Research Committee, 6. .
Library and Museum Committee, 6.
Scientific and Industrial Research Committee, 6.
HtJBST, J. E., on die-casting of aluminium -bronze, 142.
elected member, 23.
HuTTON, Dr. R. S., appointed representative to Refractories Research and
Standards Committee, 9.
elected member of council, 19.
on an electric resistance furnace for melting in crucibles, 4.
member of Committee on Increased Membei-ship, 7.
seconds vote of thanks to president, 31.
I.
Ingalls, W. N., abstract of paper by, 249.
Instone. Arthur Brian, elected member, 23.
loNiDES, A. C, on principles and methods of a new system of gas-firing, 4.
J.
Jackson John, elected member, 26.
Jeffries, Professor Zay, note on the eSect of great hydrostatic pressure on the
physical properties of metals, 4.
Zay, abstract of paper by, 240.
Jenkin, Commr. C. F., R.N.V.R., on an investigation on unsound castings of
Admiralty bronze (88 : 10 : 2) ; its cause and the remedy, 177.
Johnson, F., on bronze and some of its modifications, 8.
on committee of Birmingham Local Section, 226.
on die-casting of aluminium-bronze, 132.
on an investigation on unsound castings of Admiralty bronze (88 : 10 : 2) ;
its cause and the remedy, 182, 194.
.• working on preparation of abstracts. 231.
J., abstract of paper by, 247.
Capt. W. Morton, fallen in war, 53.
Johnston, John, elected member, 23.
JoNSON, E., abstract of paper by, 253.
JuDD, George Harold, elected member, 26.
K.
Kahn, K. D., abstract of paper by, 241.
Kay, James, elected member, 26.
Kelbee, C, abstract of paper by, 243.
Kewley, J., abstract of paper by, 264.
KiNCAiD, James Scott, elected member, 26.
King, James Foster, elected member, 26.
Name Index 311
Kipling, Herbert Spencer, elected member.
Kbeuann, abstract of paper by, 256.
Kbopsch, R., abstract of paper by, 256.
Ktjkosawa, R., abstract of paper by, 256.
L.
Lackie, William Walker, elccicd member, 27.
Laisg, a., becomes Commander of the Order of the British Empire, 0.
Lantsbekry, F. C. a. H., elected chairman of Birmingham Local Section, 226.
Paper on " The scope of the works laboratory," 225.
Lea, Professor Frederick Charles, elected member, 23.
Lee, R. E., abstract of paper by, 271.
Ley, H., abstract of paper by, 269.
LiBERi, G., abstract of paper by, 271
LoBNiTz, Fred., elected member, 27.
Lockhead, Edwin Hill, elected member, 27.
LoESCH, H. G., abstract of paper by, 289.
Logan, Arthm-, elected student, 28.
LoNGAiTJiR, Dr. Percy, on an investigation on unsound castings of Admiralty bronze
(88 : 10 : 2) ; its cause and the remedy, 194. ,
Lonsdale, Lieut. Harry, M.C., elected member, 27.
McCabe, C. R., abstract of paper by, 268.
McKeohnie, James, becomes Knight Commander of the British Empire, 9.
MacLellan, Alexander Stephen, elected member, 27.
McPhail, Daniel, elected member, 27.
McPherson, John, elected member, 27.
McQuistan, Andrew Nisbet, elected member, 27.
Main, Eng. -Commander R., fallen in war, 53.
Martin, Francis Grimshaw, elected member, 27.
James Alastair, elected student, 28.
Mathewson, E. p., abstract of paper by, 263.
Mazzetti, C, abstract of paper by, 291.
Mazzucchelli, Professor A., working on preparation of abstracts, 23 L
Meghan, Henry, elected member, 27.
Meneghini, D., abstract of paper by, 260.
Merz, Charles Hcsterman, elected member, 23.
Methley, Bernard Willoughby, elected member, 27.
Meybrey, Herbert John, elected member, 23.
Meyrick, L. J., on committee of Birmingham Local Section, 226.
Miller, S. W., note on the use of chromic acid and hydrogen peroxide as an
etching agent, 4.
Milltngton, W. E. W., on an investigation on unsound castings of Admiralty
bronze (88 : 10 : 2) ; its cause and the remedy, 196.
Miolati, A., abstract of paper by, 260.
MoREWOOD, Joseph Latham, elected member, 27.
Morrison, W. Murray, member of Library and Museum Committee, 6.
Scientific and Industrial Research Committee, 6.
seconds vote of thanks to Honorary Treasurer, 19.
B12 Name Index
MuNTZ, Sir Gerard, Bart., member cf Nomenclature Committee, 6.
Murray, M. Thornton, on an investigation on unsound castings of Admiralty
bronze (88 : 10 : 2) ; its cause and the remedy, 178, 197.
N.
Narracott, Capt. R. W., fallen in war, 53.
Neilson, Hugh Edwin Beaumont, elected member, 27.
Nose, J., abstract of paper by, 251.
o.
Odgers, R. B., death of, 3.
Osborne, Magnus, elected member, 27.
Mark, elected member, 27.
P.
Page, Arthur Reginald, elected student, 29.
Palmer, Charles Alfred, elected member, 23.
Parker, James Frederick, elected member, 23.
W. B., on die-ca.sting of aluminium bronze, 139,
on an investigation on unsound castings of Admiralty bronze (88 : 10 : 2)
its cause and the remedy, 198.
Parravoano, N., abstract of paper by, 291.
Patch, Nathaniel K. B., elected member, 23.
Patrick, Philip Walwin, elected member, 28.
Peakman, p., on die-casting of aluminium-bronze, 133.
elected member, 28.
Philip, A., member of Library and Museum Committtoe, G.
Pierce, E. H., abstract of paper by, 237.
PiLCHER, R. B., book by, 292.
Pile, Frank Seymour John, elected member, 28.
PiLON, H., abstract of paper by, 243.
POPPLETON, G. G., re-elected auditor, 29.
PoRTEViN, abstract of paper by, 245, 252.
President. See Carpenter, Professor H. C. H.
Preston, Frederick P., becomes Knight Commander of the British Empire, 9.
Primrose, H. S., on an investigation on unsound castings of Admiralty bronze
(88 : 10 : 2) ; its cause and the remedy, 204.
on metal melting in a simple crude oil furnace, 4.
Q.
QuiN, L. H., book by, 293.
Name Index 313
R.
Ramsay, Wm., on an investigation on unsound castings of Admiralty bronze
(88 : 10 : 2) ; its cause and the remedy, 206.
Rawdon, H. S., abstract of paper by, 265.
Rawlinson, W., abstract of paper by, 285.
Reason, H. L., on coke fired furnaces, 3.
on committee of Birmingham Local Section, 226.
Paper on " Copper alloys, brass and bronzes," 225.
Regan, W., abstract of paper by, 267.
Reichbl, Y. H., abstract of paper by, 271.
Reid, E. W., abstract of paper by, 270.
Rhodes, John Henry, elected member, 23.
RiciHEDs, J. W., abstract of paper by, 232, 244.
Rix, H.—
Paper on "Die-casting of aluminium -bronze," 36; advantages of die-
casting, 123 ; metals employed, 123 ; brass and bronze die-casting, 124 ;
heat treatment, 128 ; mat«rial for dies, 129 ; cost of process, 130 ; die-
ca-sting on a scientific ba.sis, 130; conclusion, 131. — Discussion: T. G. Hir.st,
132 ; F. Johnson, 132 ; P. Peakman, 133 ; Professor C. A. Edv/ards, 134 ;
Dr. W. Rosenhain, 135 ; J. Dewrance, 137 ; Professor Carpenter, 138, 140. —
Reply to Discussion, 138-141. — Communications : J. E. Hurst, 142. — R'>.pbj
to Communicafions, 143.
RoBBA, Wm. Hugh Francis, elected member, 28.
RoLFE, R. T., on an investigation on unsound castings of Admiralty bronze-
(88 : 10 : 2) ; its cause and the remedy, 208.
RooxEY, Thomas Edmund, elected member, 23.
Rose, Sir Thomas, appointed representative on Board of Scientific Societies, 9
on Committee on Standards of Non-Ferrous Metals and Alloys, 7.
■ — elected vice-president, 19.
member of library and Museum Committee, 6.
• Publication Committee, 5.
proposes vote of thanks to president, 31.
Rosenhain, Dr. W., on Beilby Prize Committee, 7.
chairman of Nomenclature Committee, 6.
on Committee on Standards of Non-Ferrous Metals and Alloys, 7.
on die-casting of aluminium-bronze, 135.
elected vice-president, 19.
on grain size, 149.
on an investigation on unsound castings of Admiralty bionze (88 : 10 ;
its cause and the remedy, 184.
member of Committee on Increased Membership, 7.
Corrosion Research Committee, 6.
Publication Committee, 5.
Scientific and Industrial Research Committee, 6.
on the relationsliip between hardness and constitution in the copper
rich aluminium-copper alloys, 103.
Ross, A. J. C, becomes Commander of the Order of the British Empire, 9.
314 Name Index
Rossi, A. J., abstract of ijaper by, 264.
RoTHWELL, H<>rb?rt, elected member, 2S
Sacher, J. F., abstract of paper by, 270.
Salvadori, R., abstract of paper by, 269.
ScHADrsroER, R., abstract of paper by, 256.
Searle, Alfred B., book by, 293.
Seaton, a. E., member of Nomenclature Committee, 6.
Scientific and Indiistrial Research Committee, 6.
report of, as Honorary Treasurer, 17.
vote of thanks to, 18.
Selby, O. E., abstract of paper by, 259.
Seligman, R., on aluminium production by electrolysis': a note on the mechanism
of the reaction, 3.
member of Committee on Increased Membership, 7.
Shaw, Frank Norminton, elected member, 23.
Hubert A., elected member, 28.
Shay, Peter Yevent, elected member, 23.
Shinjo, Yashio, elected meml)er, 23.
Shull, F. G., abstract of paper by, 256.
Smith, Enoch John, elected member, 24.
H. M., becomes Member of the Order of the British Empire, 9.
Sydney W., ou surface tension and cohesion in metals and alloys, 3.
Sir William, chairman of Library and Maseum Committee, 6.
— on Committee on Standards of Non-Ferrous Metals and Alloys, 7.
elected member of council, 19.
member of Corrosion Research Committee, 6.
Finance and General Purposes Committee. 5.
Publication Committee, 5.
Smits, A., abstract of paper by, 243.
Sneed, M. C, abstract of paper by, 274.
Spear, E. B., abstract of paper by, 240.
Spittle, A., on committee of Birmingham Local Section, 226.
Stegemax, W., abstract of paper by, 242.
Steinmetz, C. p., abstract of paper by, 280.
Stillman, a. L., abstract of paper by, 284.
Stokes, F. Wilfrid S., becomes Knight Commander of the British Empire^ 9
Sumner, Leonard, member of Corrosion Research Committee, 6.
Sutton, Hubert, elected student, 29.
SwANSON, John Henry, elected member, 24.
Swisher, C. L., abstract of paper by, 237.
T.
Taylor, Eng.-Capt. C. S., fallen in war, 54,
Edgar Willmott, elected member, 28.
Tetsex, T., note on a new producer gas-fired crucible furnace, 4.
Name Index 315
Thompson, C. A., abstract of paper by, 232.
F. C, abstract of paper by, 246.
:- on the annealing of nickel-silver, 3.
on the relatioaship between hard ness and constitution in the copper rich
aluminium -copper aUoys, 118.
M. de Kay, abstract of paper by, 288.
Thornton, H. M., contribution to metal melting discussion, 3.
ToMLiNSON, F., member of Scientific and Industrial Hesearch Committee. 6.
Tbavers, abstract of paper by, 274.
Teeasuber. See Seaton, A. E.
Tucker, S. A., abstract of paper by, 289.
TuNOAY, J., abstract of paper by, 250.
TtTRNER, Gilbert, elected member, 24.
Professor T., chairman of Finance and Gen=5ral Purposes Committee, 5.
on the hardening of metals by work, 8.
on hardness and hardening, 4.
on Honorary Trea-iurer's report, 17, 18.
on an investigation on unsoimd castings of Admiralty bronze (88 : 10 : 2)
its cause and the remedy, 176, 189.
lecture on the scientific spirit in the metal trades, 225.
member of Committee on Increased Membership, 7.
Corrosion Research Committee, 6.
Nomenclatuie Committee, 6.
Publication Committee, 5.
Scientific and Industrial Research Committee, 6.
past chairman of Birmingham Local Section, 226.
on the relationship between hardness and constitution in the copper rich
aluminium-copper alloys, 106.
William Glasier, elected member, 28.
Van Brettkeleveen, M., abstract of paper by, 272.
Van N.4ME, R. G., abstract of paper by, 245.
VicKEBS, C, abstract of paper by, 278.
VowLKS, Thomas, elected student, 24.
w.
Wagnee, William George, elected member, 24.
Walter, C. M., on high-pressure gas melting, 3.
Paper on " Pyrometry and its application in the metal trades," 225.
Ward, Joseph Stanley, elected member, 28.
Watson, Herbert John, elected member, 28.
Webb, S., book by, 293.
WiiB, WiHiam, made a knight, 8.
member of Finance and General Purposes Committee, 6.
Welbouen, B., abstract of paper by, 237,
316 Name Index
Wf.lch, John B., elected member, 24.
Welo, L. a., abstract of paper by, 252.
WinTAKER, H. —
Paper on " Die-casting of aluminium-bronze," 36 ; advantages of die-
casting, 123 ; metals employed, 123 ; brass and bronze die-casting, 124 ;
heat ti-eatment, 128 ; material for dies, 129 ; cost of process, 130 ; die-
casting (m a scientific basi.s, 130 ; conclasion, 131. — Discus.non : T. G. Hirst,
132 ; F. Johnson, 132 ; P. Peakman, 133 ; Professor C. A. Edwards, 134 ;
Dr. W. Rosenhain, 135 ; J. Dewrance, 137 ; Professor Carpenter, 138, 140. —
Reply to Discusdion, 138, 141. — Commnnications : J. E. Hurst, 142. — Reply
to Cowmunicatlons : 143.
White, A. E., abstract of paper by, 203.
WiECHOWSKT, S., abstract of paper bj', 245.
WiGGiN, Sir Henry, Bart., death of, 3.
Wilkinson, Isaac, elected student, 29.
WiLLAKD, H. H., abstract of paper by, 270.
Williams, H. M., abstract of paper by, 260.
Wilton, John Boswell, elected member, 28.
Wood, R. A., abstract of paper by, 257.
Worthing, abstract of paper by, 247.
WtJRSCHMiDT, J., abstract of paper by, 23G. '
Y.
Yarrow, H. E., becomes Commander of the Order of the Briti-sh Empire, 9.
YateS; George, elected member, 24.
Young, H. J., on an investigation on unsound castings of Admiralty bronze
(88 : 10 : 2) ; its cause and the remedy, 212.
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